Trigger marking for previous version when PR from dependabot with version update is merged

Author: Oleg

.github/workflows/build.yml

@@ -139,17 +139,23 @@ jobs:
         if: github.event_name == 'push' && github.ref == 'refs/heads/main'
 
   mark-previous-version:
-    needs: [build, meta]
+    needs: [build, meta, automerge]
     runs-on: ubuntu-latest
 
-    if: github.event_name == 'push' && github.ref == 'refs/heads/main' && needs.build.outputs.current-version != needs.meta.outputs.latest-version
+    if: |
+      (
+        (github.event_name == 'push' && github.ref == 'refs/heads/main')
+        || (github.event_name == 'pull_request' && github.event.pull_request.user.login == 'dependabot[bot]')
+      )
+      && needs.build.outputs.current-version != needs.meta.outputs.latest-version
+      && !cancelled()
 
     permissions:
       contents: write
 
     env:
       TAG: v${{ needs.meta.outputs.latest-version }}
-      COMMIT: ${{ github.event.before }}
+      COMMIT: ${{ github.event.pull_request.base.ref || github.event.before }} # either the PR base ref or previous commit in the branch
       GH_REPOSITORY: ${{ github.repository }}
 
     steps: