[BUG]: Post-commit workflow will give the PR an error status even if nothing is wrong

[FrankLeeeee]

🐛 Describe the bug

To make it easier for external contributors to contribute to our project, we have made the pre-commit into "post-commit" to auto-format the changed files when a PR is merged. However, the workflow reports an error when all files are actually well-formatted since there is nothing to format and commit. As a result, the related PR will show a "x" on its status, signifying that the PR has CI errors but in fact this error should be allowed.

One example is #2996 .

Environment

No response