Update _update-readme.yml

.github/workflows/_update-readme.yml

@@ -28,7 +28,7 @@ jobs:
         if: ${{ !env.ACT }}
         run: |
           git add README.md
-          git commit -m "[Bot] Update README.md"
+          git diff-index --quiet HEAD || git commit -m "[Bot] Update README.md"
           git status
           git push -u origin ${{ steps.create-branch-name.outputs.branch_name }}
       - uses: tibdex/github-app-token@v1