doc building broken on Python 3.11

[jugmac00]

          Looks like we have an issue in combination with the `furo` theme

Extension error (furo):
Handler <function _html_page_context at 0x7fbb82980ae0> for event 'html-page-context' threw an exception (exception: This documentation is not using `furo.css` as the stylesheet. If you have set `html_style` in your conf.py file, remove it.)

FWIW, we do not use html_style in our conf.py.

@pradyunsg Do you have an idea why this breaks now? It looks like it still worked a couple of days ago, and curiously both the failing and the working build was with furo==2023.7.26, and our conf.py did not change in the last 3 months.

Originally posted by @jugmac00 in #3094 (comment)

[gaborbernat]

This is upstream issue, pradyunsg/furo#693. We'll just wait for a fix release.

[jugmac00]

Oh right - I looked into "issues", but that project uses "discussions" for bug reports, that is why I did not see it.