build: support python3.14 and drop python3.8

[ikrommyd]

Closes #297

[nsmith-]

Can you add pyproject.toml to the watched files to trigger the wheel test at: https://github.com/cms-nanoAOD/correctionlib/blob/master/.github/workflows/wheels.yml#L10 ?
I want to see if cibw is happy with the changes there

[ikrommyd]

@nsmith- I see build failure for 314t but given #284, I see that we should be skipping free-threaded builds atm.

[nsmith-]

Thanks for the modernize as well!

[ikrommyd]

Thanks for the modernize as well!

No worries! It would be nice to have a release with the cp314 wheels soon. Then numba just needs to make their pre-release an actual release and we got coffea working on cp314 without the need to compile anything. I don't know if you wanna merge do the free-threaded building first before a release though.

[nsmith-]

I suppose #284 needs a rebase now. @lgray are you interested in doing that?
If it magically works now, maybe we can put it in. But it seemed to have issues

[lgray]

Sure no problem rebasing it.