DEP: upgrade cibuildwheel to 4.0.0

[neutrinoceros]

No description provided.

[neutrinoceros]

I recommend upgrading other GHA dependencies as well and publishing every upgrade at once as a new major release.

[Cadair]

(This is a moot point as we are doing a major release for #397 anyway)

Why do you think this should be a major release of the workflows? Is there a breaking change in cibw 4?

[neutrinoceros]

Several https://github.com/pypa/cibuildwheel/releases/tag/v4.0.0
Most notably, support for Python 3.8 and 3.13t is gone

[Cadair]

I'm not sure if in general breaking changes in downstream actions should warrant major bumps for us, that would mean we do major bumps a lot. I think a clear changelog showing which actions get bumped should be enough.

[neutrinoceros]

breaking changes in downstream actions

You mean "upstream" I think. I'm not arguing for every major change to translate as a major release here, but I do think that the ones that have user-visible impact should.

that would mean we do major bumps a lot.

Well, version numbers are cheap (virtually free), so I don't really get that argument.