Enable free-threaded wheel builds

[ngoldbaum]

Fixes #101

Thanks for working with me on this, myself and @davidhewitt were able to catch a number of issues with packaging free-threaded wheels for rust/python/pyo3 packages using this and some of the pydantic and cryptography dependencies.

At least on my fork, I'm able to successfully build free-threaded wheels using this commit.

Note that this contains an unrelated change to the sdist generation on CI, because that was unnecessarily installing a bunch of different python versions.

🥳

[Julian]

Hooray!

Thanks for working with me on this

Thank you for pushing it forward, it never would have happened otherwise (not least of which because this isn't functionality I care about, but I'm very happy to support it in exactly the case that happened, i.e. you helping!)

The changes here (including what you noted) match what I did on the ft-wheels branch, which I didn't merge because it was/is waiting on twine to unbreak itself. It looks like that has now happened considering we're green, so I'll merge.

Thanks again. P.S. I'd offer you commit bit on this repo if you'd like to continue to help out in any way with this sort of thing -- though of course it's a blessing and a curse as with anything. But just mentioning that I appreciate it! Ping if you care for it.

[Julian]

pypa/trove-classifiers#195 looks unmerged, so no trove classifier to add it seems yet. But a release will go out in a minute.

[ngoldbaum]

But just mentioning that I appreciate it! Ping if you care for it.

Thanks for the offer, hopefully support is pretty much autopilot from here. Let's not give me a commit bit unless this package comes up again.