Drop use of build_sphinx distutils command

[stephenfin]

Drop use of the build_sphinx distutils command, which was dropped in Sphinx 7.x. distutils itself is deprecated and will be removed in Python 3.12.

While we're here, we also fix up some other issues with tox and the setup files in general. The commit messages hold more information about this.

[stephenfin]

Depends on #1329.

[tobias-urdin]

@stephenfin thanks, this all looks good to me except for removal of docs-gnocchi-web tox env. I think that's used somehow to roll out https://gnocchi.osci.io but I don't have access to that so I'm not sure. It's also building that but ignoring warnings to not fail I guess(?).

Can we leave that in and fix the conflict and I'll pull this in asap to unblock sphinx7, thanks!

[stephenfin]

@stephenfin thanks, this all looks good to me except for removal of docs-gnocchi-web tox env. I think that's used somehow to roll out gnocchi.osci.io but I don't have access to that so I'm not sure. It's also building that but ignoring warnings to not fail I guess(?).

Can we leave that in and fix the conflict and I'll pull this in asap to unblock sphinx7, thanks!

Done. I think the failure is unrelated but I can't rerun it to check.

[tobias-urdin]

Figured out it's handled from here: https://gitlab.com/osci/community-cage-infra-ansible/-/blob/master/roles/gnocchi_builder/templates/gnocchi_builder

[tobias-urdin]

Sorry for all the resistance @stephenfin – please rebase after revert https://github.com/gnocchixyz/gnocchi/pull/1343

[stephenfin]

@tobias-urdin Anything else needed here or can we merge this (I'd like to get it off my TODO list :smile:)?

[tobias-urdin]

@stephenfin Thanks!