ImportError: lxml.html.clean module is now a separate project lxml_html_clean.

[david26694]

Getting:

  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/mkdocs_jupyter/convert.py", line 1, in <module>
    from nbconvert.filters.markdown_mistune import IPythonRenderer
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/nbconvert/__init__.py", line 5, in <module>
    from .exporters import *
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/nbconvert/exporters/__init__.py", line 1, in <module>
    from .asciidoc import ASCIIDocExporter
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/nbconvert/exporters/asciidoc.py", line 9, in <module>
    from .templateexporter import TemplateExporter
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/nbconvert/exporters/templateexporter.py", line 25, in <module>
    from lxml.html.clean import clean_html
  File "/opt/hostedtoolcache/Python/3.8.18/x64/lib/python3.8/site-packages/lxml/html/clean.py", line 18, in <module>
    raise ImportError(
ImportError: lxml.html.clean module is now a separate project lxml_html_clean.
Install lxml[html_clean] or lxml_html_clean directly.

in this github action: https://github.com/david26694/cluster-experiments/actions/runs/8936095534/job/24545792610

I think it has to do with mkdocs_jupyter not using lxml_html_clean, but I may be wrong. Wdyt?