ci: Update group to use only ref

Author: caffeine-addictt

.github/workflows/test-worker.yml

@@ -18,7 +18,7 @@ permissions:
   contents: read
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs: