Error with clean up script

Our [clean up script](https://github.com/skops-dev/skops/blob/main/scripts/clean_skops.py) for https://huggingface.co/skops-ci currently [fails](https://github.com/skops-dev/skops/actions/runs/4749758738/jobs/8437312086), we're investigating. Apart from fixing the issue, the clean up script should also take care of cleaning up spaces, not only models.