set to on pull-request for testing

.github/workflows/sync_submodules.yml

@@ -1,9 +1,17 @@
 name: Update Submodules
 
+# on:
+#   workflow_dispatch: # Allow manual triggering
+#   schedule:
+#     - cron: '0 0 * * *'  # Execute at midnight every day
 on:
-  workflow_dispatch: # Allow manual triggering
-  schedule:
-    - cron: '0 0 * * *'  # Execute at midnight every day
+  pull_request:
+    branches:
+      master
+
+  concurrency:
+    group: ${{ github.head_ref || github.run_id }}
+    cancel-in-progress: true
 
 jobs:
   check_update_submodule_branch: