ImportError: cannot import name '_RelativePathExtension' from 'mkdocs.structure.pages'

Hi, This import is now invalid: https://github.com/greenape/mknotebooks/blob/master/mknotebooks/plugin.py#L17 This changed in PR https://github.com/mkdocs/mkdocs/pull/3283 that was released in `mkdocs` [1.5.0](https://github.com/mkdocs/mkdocs/releases/tag/1.5.0) last week. I have just discovered that in this GitHub Actions pipeline exection: https://github.com/PyFPDF/fpdf2/actions/runs/5731678301/job/15533085644