Handle case when no tag has changed

Author: Ariouz

.github/workflows/ci-unittest-retagger.yml

@@ -75,4 +75,4 @@ jobs:
         run: |
           git push --set-upstream origin weekly_retagger_${{ github.run_id }}
           gh label create "weekly-retagger" --color "BDDFDF" -d "[DO NOT ADD] Automatically set to weekly retagger PR" || echo "Label 'weekly-retagger' already exists"
-          gh pr create -B master --title "[WORKFLOW] Weekly Retagger: Update tags" --body "Applied weekly retags on $os_list" -l "weekly-retagger"
+          gh pr create -B master --title "[WORKFLOW] Weekly Retagger: Update tags" --body "Applied weekly retags on $os_list" -l "weekly-retagger" || echo "Nothing to push"