update contrib build

.github/workflows/update_contributors.yml

@@ -7,6 +7,7 @@ on:
 
 jobs:
   update_contributors:
+    if: github.event_name == 'push' && contains(fromJson('["refs/heads/master", "refs/heads/main"]'), github.ref)
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code