Don't re-trigger on self-push

.github/workflows/update.yml

@@ -13,6 +13,8 @@ concurrency:
 jobs:
   update_nur:
     runs-on: ubuntu-latest
+    # Don't trigger when the last push was done by a bot
+    if: github.event_name != 'push' || endsWith(github.actor, '[bot]')
     steps:
     - id: get_workflow_token
       uses: peter-murray/workflow-application-token-action@v4.0.1