Outdated tooling and support of Python >= 3.12

[phettberg]

I need support for Python 3.12 and 3.14 and in the best case I'll get deprecation warnings, but also really errors.

• Pytest
• Mypy
• Pylama

The problem is, that some of the used tools also struggle to keep up with deprecations or changes of libraries they're using themselves.

I'm going to try to fix this as well as I can. But I also consider moving to ruff and ditching the linting and codestyle check tools ...

[semiversus]

Yes, fine. Most of the incompatabilities for specific Python version are coming from the tools like linter. Dropping support of old Python version and changing the set of tools is fine for me.