Consider dropping Python 3.9 and 3.10 support

[phi-friday]

Python 3.9 is already EOL, and 3.10 is close to EOL too. Continuing to support them likely makes dependency management and code modernization harder than necessary.
I can also contribute the related changes if maintainers agree with this direction.

eol ref: https://devguide.python.org/versions/
(3.9: 2025-10, 3.10: 2026-10)

[t-muser]

I'm trying to keep support for versions that are on security support. So happy to phase out Python 3.9, but I'd prefer to keep support for 3.10 until end of October. What do you think?

[phi-friday]

It’s entirely up to the maintainer’s preference, so you can choose whatever approach is most convenient. The reason I specifically mentioned 3.10 was not for any particular reason other than that support for it will soon end, and a certain development dependency branches its behavior based on 3.10.

    "sphinx>=7.0.0; python_version<'3.10'",
    "sphinx>=8.0.0; python_version>='3.10'",
    "sphinx-autodoc-typehints>=2.3.0; python_version<'3.10'",
    "sphinx-autodoc-typehints>=2.4.0; python_version>='3.10'",