Bump python version due to biopython pin clash

[Desperadus]

When one wishes to install this on python 3.8 which in the pyproject.toml was declared to be okay with version >=3.8 one gets error:

 No solution found when resolving dependencies for split (markers: python_full_version == '3.8.*'):
  ╰─▶ Because the requested Python version (>=3.8) does not satisfy Python>=3.9 and biopython==1.84 depends on Python>=3.9,
      we can conclude that biopython==1.84 cannot be used.
      And because alphabase[stable] depends on biopython==1.84 and your project requires alphabase[stable], we can conclude
      that your project's requirements are unsatisfiable.

So I bump the pyproject.toml python version to 3.9

[lucas-diedrich]

Seems to break the pre-commit workflow, see #432 #433

[lucas-diedrich]

We should also end support for python 3.9 at some point as it has reached its end-of-life (and python 3.10 will soon for that matter)

https://devguide.python.org/versions/

[mschwoer]

superseded by #442