`tox -e docs` fails on git master

[mgedmin]

$ tox -e docs

docs: commands[0]> sphinx-build -b html -d docs/_build/doctrees docs docs/_build/html
Running Sphinx v8.0.2
WARNING: Invalid configuration value found: 'language = None'. Update your configuration to a valid language code. Falling back to 'en' (English).
loading translations [en]... done
WARNING: html_static_path entry '_static' does not exist
Converting `source_suffix = '.rst'` to `source_suffix = {'.rst': 'restructuredtext'}`.
ERROR: Invalid value `None` in intersphinx_mapping['https://docs.python.org/']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopeinterface.readthedocs.io/en/latest']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopeevent.readthedocs.io/en/latest/']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopecomponent.readthedocs.io/en/latest/']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopelocation.readthedocs.io/en/latest/']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopecontainer.readthedocs.io/en/latest/']. Expected a two-element tuple or list.
ERROR: Invalid value `None` in intersphinx_mapping['https://zopesite.readthedocs.io/en/latest/']. Expected a two-element tuple or list.

Configuration error:
Invalid `intersphinx_mapping` configuration (7 errors).
docs: exit 2 (0.55 seconds) /home/mg/src/zopefoundation/zope.publisher> sphinx-build -b html -d docs/_build/doctrees docs docs/_build/html pid=637816
  docs: FAIL code 2 (1.38=setup[0.83]+cmd[0.55] seconds)
  evaluation failed :( (1.43 seconds)

[mgedmin]

Actually, applying the latest meta config fixes tox -e docs (but breaks tox -e lint and tox -e release-check), so I'll try to go that route.

[mgedmin]

tox -e release-check is happy if I normalize the supported Python versions with check-python-versions --drop 3.7 --add 3.12, but tox -e lint wants to reformat half of the codebase and then fails with an error that is hidden by a voluminous diff, leaving the source tree full of uncommitted changes.

I'm not a fan of tox -e lint making actual changes to actual source files.

[icemac]

To update to the currently supported Python versions meta/config/update-python-support.py might come handy as it does everything needed in one go.

[mgedmin]

Okay, I'm confused. I merged the PR, git pulled from github, ran tox p, and I'm once again seeing the docs failures about intersphinx_mapping. How come?

I'm was sure they were fixed by the meta/config/config-package.py changes, since it ran tox for me, and it wouldn't have committed/pushed if tox had failed. I should've dug deeper.