Avoid failure in `check_repo.py` due to missing backends (#21930)
* Update utils/check_repo.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
* Update utils/check_repo.py
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>
---------
Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>
Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>