SPEC 0: drop support for python 3.10 by 2026-10-31

[github-actions]

Python 3.10 is due to reach end-of-life on 2026-10-31 (within window). Update pyproject.toml and related workflow files to drop this version, and consider raising the maximum supported version if a newer Python release is available.

This issue was opened automatically by the nightly SPEC 0 check (.github/workflows/spec0_check_nightly.yml). If there's a specific reason to keep supporting this version, close this issue with an explanation. Otherwise, leave it open until the minimum version is bumped.

[genedan]

I created a new branch #1350-update-dependencies. We can wait until Python 3.15 comes out before I create a PR.