Support freethreaded builds on windows (python 3.14t)

[laramiel]

Would it be possible to release a python 3.14t build of ml_dtypes for windows?

It was added to CIBW_SKIP last year here: 9b22feb

[laramiel]

An idea: Could ml_dtypes use the python limited api? That may simplify supporting multiple python versions.

https://docs.python.org/3/c-api/stable.html#limited-c-api

[hawkinsp]

@laramiel I've tried in the past (#195) but I was somewhat concerned it might cause problems with a separate change that I'd like to do to switch to using NumPy 2.0 dtype APIs. I'm not ruling out reviving that PR, though.

Also it doesn't apply to free threading, there is no stable ABI for free threaded builds at this time in CPython.

[laramiel]

I agree that it would not solve the freethreaded issue.

I was thinking that other than the PyUnstable_Module_SetGIL(m.get(), Py_MOD_GIL_NOT_USED); line, ml_dtypes does not appear to use anything beyond the limited api at the moment, so you could reduce the build matrix.

[jbms]

Thanks. Can you create a release with windows 3.14t builds?

[jakevdp]

Thanks. Can you create a release with windows 3.14t builds?

I'll plan to do a new release on Monday.

[jakevdp]

We just released version 0.5.4 with 3.14 free-threading wheels on Windows: https://pypi.org/project/ml-dtypes/0.5.4/#files