[kytta]

This PR adds support for Python 3.15. To adhere to the usual release cadence, it also drops the EOL Python 3.10. All tests that ran under 3.10 now run under 3.11. Lockfile has been updated to include updates for packages that have gained cp315 wheels (so that we don't build them from scratch):

$ git pkgs diff master
Modified:
  ~ charset-normalizer 3.4.9 -> 3.5.2 (uv.lock)
  ~ coverage 7.15.2 -> 7.17.2 (uv.lock)
  ~ cryptography 49.0.0 -> 50.0.2 (uv.lock)
  ~ hypothesis 6.161.0 -> 6.170.15 (uv.lock)
  ~ librt 0.13.0 -> 0.16.0 (uv.lock)
  ~ markupsafe 3.0.3 -> 3.0.4 (uv.lock)
  ~ nh3 0.3.6 -> 0.3.7 (uv.lock)

Removed:
  - exceptiongroup 1.3.1 (uv.lock)
  - tomli 2.4.1 (uv.lock)

I've ran all tests (tox run / tox p), and all pass locally

[Kriechi]

Thanks! 🎉