Squashed commit of the following:

commit 84e31bd
Author: Christina Lee <chrissie.c.l@gmail.com>
Date:   Fri Sep 9 09:22:56 2022 -0700

    Defer op-arithmetic to default qubit (#349)

    * defer op-arithmetic to default qubit

    * Auto update version

    * tests, changelog, black

    * differentiation tests

    * black

    Co-authored-by: Dev version update bot <github-actions[bot]@users.noreply.github.com>

commit 3b78924
Author: Matthew Silverman <ma.silv11@gmail.com>
Date:   Tue Aug 30 08:48:53 2022 -0400

    remove `supports_reversible_diff` (#342)

    * remove unused option

    * Auto update version

    Co-authored-by: Dev version update bot <github-actions[bot]@users.noreply.github.com>

commit 6958fb8
Author: Amintor Dusko <87949283+AmintorDusko@users.noreply.github.com>
Date:   Mon Aug 29 09:36:08 2022 -0400

    Quick fix for upload artifact for win (#346)

    * fix upload artifact for win

    * update changelog

commit 66429b0
Author: Rashid N H M <95639609+rashidnhm@users.noreply.github.com>
Date:   Sat Aug 27 21:28:06 2022 -0400

    Updated ReadTheDocs bade to new url (#339)

    * Updated ReadTheDocs bade to new url

    * Auto update version

    * Auto update version

    Co-authored-by: Dev version update bot <chae-yeun@xanadu.ai>
    Co-authored-by: Josh Izaac <josh146@gmail.com>
    Co-authored-by: Dev version update bot <github-actions[bot]@users.noreply.github.com>

commit f1a6789
Author: Amintor Dusko <87949283+AmintorDusko@users.noreply.github.com>
Date:   Fri Aug 26 13:41:14 2022 -0400

    Update cancel-workflow-action and bot credentials (#345)

    * update bot credentials

    * update cancel-workflow-action

commit b594234
Author: Lee James O'Riordan <mlxd@users.noreply.github.com>
Date:   Fri Aug 26 09:21:15 2022 -0400

    Update tagger bot for latest release (#344)

    * Update tagged CI for releases

    * Auto update version

    * Update changelog [skip_ci]

    Co-authored-by: Dev version update bot <chae-yeun@xanadu.ai>

commit 8265edd
Author: Amintor Dusko <87949283+AmintorDusko@users.noreply.github.com>
Date:   Thu Aug 25 10:59:45 2022 -0400

    Caching Kokkos build for wheel-builds (#316)

    * introduce caching Kokkos for wheels

    * improve process_options file

    * isolate Kokkos installation

    * offload windows wheel build to cibuildwheel

    * update PennyLane-Lightning build

    Co-authored-by: Lee James O'Riordan <mlxd@users.noreply.github.com>
    Co-authored-by: Lee J. O'Riordan <lee@xanadu.ai>

commit 2282f9f
Author: Chae-Yeun Park <chae-yeun@xanadu.ai>
Date:   Wed Aug 24 10:07:59 2022 -0400

    Exclude AVX512 lines from codecov (#340)

    * Add expval(ham) forward

    * Fix namespace

    * Auto update version

    * Trigger CI

    * Unwrap ArrayBox

    * Format

    * Trigger CI

    * Remove irrelevant file

    * Update for CodeCov

    * Auto update version

    * Retry for AVX2

    * Retry for AVX2

    * Retry for AVX2

    * Retry for AVX2

    * Retry for AVX2

commit 9bad592
Author: Chae-Yeun Park <chae-yeun@xanadu.ai>
Date:   Tue Aug 23 18:07:46 2022 -0400

    Add Hamiltonian expval in the forward path (#333)

    * Add expval(ham) forward

    * Fix namespace

    * Auto update version

    * Trigger CI

    * Unwrap ArrayBox

    * Format

    * Trigger CI

    * Auto update version

    * Remove irrelevant file

    * Auto update version

    * Update pennylane_lightning/src/algorithms/JacobianTape.hpp

    Co-authored-by: Lee James O'Riordan <mlxd@users.noreply.github.com>

    * Update changelog

    Co-authored-by: Lee James O'Riordan <mlxd@users.noreply.github.com>

commit c443592
Author: Josh Izaac <josh146@gmail.com>
Date:   Tue Aug 23 11:11:50 2022 -0400

    Update docs URL (#335)

    * Update docs URL

    * Auto update version

    * Auto update version

    * update navbar

    Co-authored-by: Dev version update bot <chae-yeun@xanadu.ai>
    Co-authored-by: Amintor Dusko <87949283+AmintorDusko@users.noreply.github.com>

commit bc54a3e
Author: Josh Izaac <josh146@gmail.com>
Date:   Tue Aug 23 02:45:02 2022 +0800

    Update conf.py

commit 1e43ace
Author: Chae-Yeun Park <chae-yeun@xanadu.ai>
Date:   Mon Aug 22 14:37:00 2022 -0400

    Fix measurement error message (#334)

    * Fix measurement error message

    * Reformat

    * Add Changelog

commit c15fa0d
Author: Amintor Dusko <87949283+AmintorDusko@users.noreply.github.com>
Date:   Thu Aug 18 10:06:32 2022 -0400

    Create a PennyLane-lightning requirements-dev.txt and update the Dockerfile (#330)

    * Create a requirements-dev.txt

    * Update tests and benchmarks

    * Improve dockerfile

commit 87538ec
Author: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Date:   Mon Aug 15 10:57:49 2022 -0400

    post release version bump (#331)

    Co-authored-by: mlxd <mlxd@users.noreply.github.com>

commit dc0d3b1
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 13:03:58 2022 -0400

    Remove redundant Win ops and pin to WS2019

commit e5755d9
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 11:39:24 2022 -0400

    Remove build base command

commit ba16ec9
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 11:32:27 2022 -0400

    Downgrade Py3.10 version to avoid additional characters in build path

commit e3f8b4e
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 11:19:56 2022 -0400

    Attempt updating Python installation package for Windows runner

commit 90c06cc
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 11:00:55 2022 -0400

    Retry forcing longpaths for W10 build

commit 36abd9b
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 10:38:24 2022 -0400

    Disable clone of Kokkos submodules to allow Windows builds to proceed

commit becd10c
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 08:45:43 2022 -0400

    Fix changelog++

commit c321d34
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Thu Aug 11 08:44:12 2022 -0400

    Fix changelog

commit c198a5d
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Tue Aug 9 12:10:44 2022 -0400

    Update version string

    Signed-off-by: Lee J. O'Riordan <loriordan@gmail.com>

commit 2dd4b80
Author: Lee J. O'Riordan <loriordan@gmail.com>
Date:   Tue Aug 9 12:08:50 2022 -0400

    Update changelog

.github/CHANGELOG.md

@@ -1,4 +1,53 @@
-# Release 0.25.0-dev
+# Release 0.26.0-dev
+
+### New features since last release
+
+### Breaking changes
+
+### Improvements
+
+* Introduces requirements-dev.txt and improves dockerfile.
+[(#330)](https://github.com/PennyLaneAI/pennylane-lightning/pull/330)
+
+* Support `expval` for a Hamiltonian.
+[(#333)](https://github.com/PennyLaneAI/pennylane-lightning/pull/333)
+
+* Implements caching for Kokkos installation.
+[(#316)](https://github.com/PennyLaneAI/pennylane-lightning/pull/316)
+
+* Supports measurements of operator arithmetic classes such as `Sum`, `Prod`,
+  and `SProd` by deferring handling of them to `DefaultQubit`.
+  [(#349)](https://github.com/PennyLaneAI/pennylane-lightning/pull/349)
+
+```
+@qml.qnode(qml.device('lightning.qubit', wires=2))
+def circuit():
+    obs = qml.s_prod(2.1, qml.PauliZ(0)) + qml.op_sum(qml.PauliX(0), qml.PauliZ(1))
+    return qml.expval(obs)
+```
+
+### Documentation
+
+### Bug fixes
+
+* Test updates to reflect new measurement error messages.
+[(#334)](https://github.com/PennyLaneAI/pennylane-lightning/pull/334)
+
+* Updates to the release tagger to fix incompatibilities with RTD.
+[(#344)](https://github.com/PennyLaneAI/pennylane-lightning/pull/344)
+
+* Update cancel-workflow-action and bot credentials.
+[(#345)](https://github.com/PennyLaneAI/pennylane-lightning/pull/345)
+
+### Contributors
+
+This release contains contributions from (in alphabetical order):
+
+Amintor Dusko, Christina Lee, Chae-Yeun Park
+
+---
+
+# Release 0.25.0
 
 ### New features since last release
 
@@ -23,6 +72,7 @@
 [(#313)](https://github.com/PennyLaneAI/pennylane-lightning/pull/313)
 
 ### Documentation
+
 * Updated ReadTheDocs runner version from Ubuntu 20.04 to 22.04 
 [(#327)](https://github.com/PennyLaneAI/pennylane-lightning/pull/327)
 
@@ -35,7 +85,7 @@
 
 This release contains contributions from (in alphabetical order):
 
-Amintor Dusko, Lee James O'Riordan, Chae-Yeun Park
+Amintor Dusko, Christina Lee, Rashid N H M, Lee J. O'Riordan, Chae-Yeun Park
 
 ---
 
@@ -702,4 +752,4 @@ Initial release.
 
 This release contains contributions from (in alphabetical order):
 
-Tom Bromley, Josh Izaac, Nathan Killoran, Rashid N H M, Antal Száva
+Tom Bromley, Josh Izaac, Nathan Killoran, Antal Száva

.github/workflows/benchmarks.yml

@@ -32,9 +32,8 @@ jobs:
         run: |
           cd main
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
+          pip install -r requirements-dev.txt
           pip install matplotlib
-          pip install git+https://github.com/PennyLaneAI/pennylane.git@master
 
       - name: Install lightning.qubit device (master)
         run: |

.github/workflows/format.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Cancel Previous Runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -35,7 +35,7 @@ jobs:
 
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -63,7 +63,7 @@ jobs:
 
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 

.github/workflows/post_release_tag_latest.yml → .github/workflows/post_release_tag.yml

@@ -5,7 +5,7 @@ on:
     types: [published]
 
 env:
-  TAG_NAME: latest
+  TAG_NAME: latest_release
 
 jobs:
   post_release_tag_latest:
@@ -18,7 +18,7 @@ jobs:
 
       - name: Overwrite tag
         run: |
-          git config --local user.email "chae-yeun@xanadu.ai"
+          git config --local user.email 'github-actions[bot]@users.noreply.github.com'
           git config --local user.name "Latest tag update bot"
           git tag -d $TAG_NAME || true
           if git push --delete origin $TAG_NAME; then

.github/workflows/tests_linux.yml

@@ -21,7 +21,7 @@ jobs:
         os: [ubuntu-20.04]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -74,7 +74,7 @@ jobs:
         os: [ubuntu-20.04]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -127,7 +127,7 @@ jobs:
         os: [ubuntu-20.04]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -181,7 +181,7 @@ jobs:
         os: [ubuntu-20.04]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -230,9 +230,7 @@ jobs:
         run: |
           cd main
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
-          pip uninstall pennylane -y
-          pip install git+https://github.com/PennyLaneAI/pennylane.git
+          pip install -r requirements-dev.txt
 
       - name: Install ML libraries for interfaces
         run: |
@@ -285,9 +283,7 @@ jobs:
         run: |
           cd main
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
-          pip uninstall pennylane -y
-          pip install git+https://github.com/PennyLaneAI/pennylane.git
+          pip install -r requirements-dev.txt
 
       - name: Install ML libraries for interfaces
         run: |

.github/workflows/tests_windows.yml

@@ -14,7 +14,7 @@ jobs:
         os: [windows-latest]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
       - uses: actions/checkout@v2
@@ -60,7 +60,7 @@ jobs:
         os: [windows-latest]
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
       - uses: actions/checkout@v2

.github/workflows/tests_without_binary.yml

@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Cancel previous runs
-        uses: styfle/cancel-workflow-action@0.4.1
+        uses: styfle/cancel-workflow-action@0.10.0
         with:
           access_token: ${{ github.token }}
 
@@ -36,9 +36,7 @@ jobs:
         run: |
           cd main
           python -m pip install --upgrade pip
-          pip install -r requirements.txt
-          pip uninstall pennylane -y
-          pip install git+https://github.com/PennyLaneAI/pennylane.git
+          pip install -r requirements-dev.txt
 
       - name: Install lightning.qubit device
         run: |

.github/workflows/update_dev_version.yml

@@ -36,8 +36,8 @@ jobs:
         run: |
           cd ./pr
           if [[ -n $(git status -s) ]]; then
-            git config --local user.email "chae-yeun@xanadu.ai"
-            git config --local user.name "Dev version update bot"
+            git config --global user.email 'github-actions[bot]@users.noreply.github.com'
+            git config --global user.name "Dev version update bot"
             git add .
             git commit -m 'Auto update version'
             git push