Remove project extras

[AA-Turner]

Purpose

Following #13073, we can now consider removing the project extras (docs, lint, and test). These were never intended for external use, but theoretically downstreams could attempt to install sphinx[blah]. As such, I've currently proposed a middle ground of removing all optional dependencies but keeping the extra names themselves. I am open to arguments to just remove them, though, or to wait on removing them.

I don't know if this has an impact on redistributors, but I imagine that they will have a larger plan for PEP 735 in the abstract.

References

• PEP 735
• Use the PEP 735 [dependency-groups] table #13073

A

[jayaddison]

@AA-Turner NB: I think one or two of the GitHub Actions CI workflows still rely on the old-style pip install .[foo] (e.g. here) - I think those might fail with these changes?