maint: bump cibuildwheel, mpfr and flint

[oscarbenjamin]

Bump version constraints for Cython 3.1.

[oscarbenjamin]

The manylinux arm job is building too many wheels. Reported at pypa/cibuildwheel#2412 so I will leave this PR open as a demonstration and make a new separate PR to fix the Cython version.

[mayeut]

By default, cibuildwheels will only build what's possible given requires-python.
I often find easier not to specify build in the configuration but only setting skip.
In this case, adding pp310-* to the skip config allows to drop the build config.

[oscarbenjamin]

Yes, that would be better. The comment above notes the awkwardness.

[mayeut]

The environment variable & toml setting are additive for enable, it might be better to keep the static config in pyproject.toml and only add cpython-prerelease in the workflow (you can also add a condition on tags if you don't want to forget to remove it before a release).

[oscarbenjamin]

Thanks. I don't think I want to have cpython-prerelease there at all actually (now that I have already confirmed that it works). For a moment it seemed like a good way to keep up to date with changes in 3.14 but actually I think it would be better just to have a job that builds fresh rather than messing with the wheel building configuration.

[oscarbenjamin]

Okay, this has produced the expected number of wheels now:

5 wheels produced in 10 minutes:
  python_flint-0.7.1-cp311-cp311-manylinux_2_28_aarch64.whl          11,292 kB
  python_flint-0.7.1-cp312-cp312-manylinux_2_28_aarch64.whl          11,200 kB
  python_flint-0.7.1-cp313-cp313-manylinux_2_28_aarch64.whl          11,186 kB
  python_flint-0.7.1-cp313-cp313t-manylinux_2_28_aarch64.whl         11,279 kB
  python_flint-0.7.1-pp311-pypy311_pp73-manylinux_2_28_aarch64.whl   10,965 kB

Thanks @mayeut for your help!