Fix auto PR for the new extension workflow (#1913)

- Don't show in changelog

Author: D8H

.github/workflows/auto-pr.yml

@@ -178,7 +178,7 @@ jobs:
 
             It can take a few seconds for the file to fully upload and show as the above. Once it is like shown above,
             click "Comment" and let the bot do the rest!
-          labels: '${{ join(github.event.issue.labels.*.name) }}'
+          labels: ✨ New extension
 
       - name: Add card to pending review
         uses: peter-evans/create-or-update-project-card@v2