Bump minimum python version

[Qup42]

Set the correct minimum python version of 3.10 in the pyproject.toml and update the unit test workflow (drop old versions and add new versions).

Python 3.10 seems reasonable. It is the oldest version that is still officially supported with updates and the oldest version that we package for. The requirement for 3.10 is caused by:

• importlib.resources.as_file and importlib.resources.files in serve_evaluation_app.py require 3.9
• platform.freedesktop_os_release in system_info.py requires 3.10

Note: This PR aligns the pyproject.toml with the code. Support for older versions is likely possible if needed. platform.freedesktop_os_release could be replaced with the distro package.

Closes ad-freiburg/qlever#2847