[Internal] Trigger the validate workflow in the merge queue

.github/workflows/message.yml

@@ -3,11 +3,16 @@ name: Validate Commit Message
 on:
   pull_request:
     types: [opened, synchronize, edited]
+  merge_group:
+      types: [checks_requested] 
 
 jobs:
-
   validate:
     runs-on: ubuntu-latest
+    # GitHub required checks are shared between PRs and the Merge Queue.
+    # Since there is no PR title on Merge Queue, we need to trigger and
+    # skip this test for Merge Queue to succeed.
+    if: github.event_name == 'pull_request' 
     steps:
       - name: Checkout
         uses: actions/checkout@v3