Add script to sync labels (microsoft#3323)

Add script to sync labels to enforce the labels designed in microsoft#3265
<img width="1050" alt="image"
src="https://github.com/microsoft/typespec/assets/1031227/5ba6a134-e6d6-4a28-9cf7-99fd27c8e89e">

.github/actions/setup/action.yml

@@ -11,7 +11,7 @@ runs:
 
   steps:
     - name: Install pnpm
-      uses: pnpm/action-setup@v2
+      uses: pnpm/action-setup@v3
 
     - name: Set node version to ${{ inputs.node-version }}
       uses: actions/setup-node@v4

.github/workflows/sync-labels.yml

@@ -0,0 +1,33 @@
+name: Sync labels
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+  push:
+    branches:
+      - "main"
+    paths:
+      - "package.json"
+      - "eng/common/labels.yaml"
+      - "eng/common/scripts/sync-labels.ts"
+      - ".github/workflows/sync-labels.yml"
+
+  workflow_dispatch: {}
+
+permissions:
+  issues: write
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/setup
+
+      - run: pnpm install
+        name: Install dependencies
+
+      - run: pnpm sync-labels --github
+        name: Sync labels
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/verify-labels.yml

@@ -0,0 +1,26 @@
+name: Verify labels
+on:
+  pull_request:
+    branches:
+      - "main"
+    paths:
+      - "package.json"
+      - "eng/common/labels.yaml"
+      - "eng/common/scripts/sync-labels.ts"
+      - ".github/workflows/sync-labels.yml"
+      - "CONTRIBUTING.md"
+
+jobs:
+  verify:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: ./.github/actions/setup
+
+      - run: pnpm install
+        name: Install dependencies
+
+      - run: pnpm sync-labels --github --check
+        name: Verify labels
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}