ci: add workflow to cancel ongoing runs on pull request merge

.github/workflows/cancel-workflow-on-merge.yml

@@ -0,0 +1,15 @@
+name: Cancel Workflow on Merge
+
+on:
+  pull_request:
+    types: [closed]
+
+jobs:
+  cancel-workflow:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Cancel Workflow if Merged
+        if: ${{ github.event.pull_request.merged }}
+        run: |
+          echo "PR has been merged, cancelling workflow..."
+          gh run cancel --repo ${{ github.repository }} --workflow "TDengine Test" --branch ${{ github.event.pull_request.base.ref }}

.github/workflows/tdengine-ci-test.yml

@@ -11,7 +11,7 @@ on:
       - 'docs/**'
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}-TDengine
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
   cancel-in-progress: true
 
 env: