Enhance changelog verifier script

Signed-off-by: Kunal Kotwani <kkotwani@amazon.com>

.github/workflows/changelog_verifier.yml

@@ -1,19 +1,43 @@
 name: "Changelog Verifier"
 on:
   pull_request:
-    types: [opened, edited, review_requested, synchronize, reopened, ready_for_review, labeled, unlabeled]
+    types: [opened, synchronize, reopened, ready_for_review, labeled, unlabeled]
 
 jobs:
   # Enforces the update of a changelog file on every pull request
-  verify-changelog:
-    if: github.repository == 'opensearch-project/OpenSearch'
+  verify-changelog-3x:
+    # if: github.repository == 'opensearch-project/OpenSearch'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           ref: ${{ github.event.pull_request.head.sha }}
-
       - uses: dangoslen/changelog-enforcer@v3
         with:
           skipLabels: "autocut, skip-changelog"
+          changeLogPath: 'CHANGELOG-3.0.md'
+  verify-changelog-2x:
+      # if: github.repository == 'opensearch-project/OpenSearch' && needs.verify-changelog-3x.result == 'failure'
+      if: needs.verify-changelog-3x.result == 'failure'
+      runs-on: ubuntu-latest
+      needs: [ verify-changelog-3x ]
+      steps:
+        - uses: actions/checkout@v4
+          with:
+            token: ${{ secrets.GITHUB_TOKEN }}
+            ref: ${{ github.event.pull_request.head.sha }}
+        - uses: dangoslen/changelog-enforcer@v3
+          with:
+            skipLabels: "autocut, skip-changelog"
+            changeLogPath: 'CHANGELOG-2.0.md'
+  overall-status:
+    # if: github.repository == 'opensearch-project/OpenSearch'
+    runs-on: ubuntu-latest
+    needs: [ verify-changelog-3x, verify-changelog-2x ]
+    steps:
+      - name: Check job statuses
+        run: |
+          if [[ ${{ needs.verify-changelog-3x.result }} == 'failure' && ${{ needs.verify-changelog-2x.result }} == 'failure' ]]; then
+            exit 1
+          fi