Pyproject toml

[rpartzsch]

Removed setup.py and reworked the build using pyproject.toml.
A few things still need to be checked and discussed I guess.

• We need to check the tests
• update versions
• updates to the dependencies,
• check with any possible conflicts for building with Python versions<3.11

Belongs to #243

[cbespin]

With #250 and soon #251, this can be rebased and tackled again, I assume. At least get the pipelines going and check if things work