Modernize packaging, add support for new python versions, prepare for 0.59.2 release

[CPBridge]

I think it makes sense to move to the pyproject.toml standard for the next release (0.59.2). This PR replaces the functionality of the following files with a new pyproject.toml:

• setup.py
• requirements_test.txt
• requirements_docs.txt
• Manifest.in
• setup.cfg (since flake8 does not support pyproject.toml yet, I cannot remove this file entirely)

The github workflows, developer guide and .readthedocs.yaml have been updated to accommodate these changes.

Additionally I added explicit support for newer python versions (3.11, 3.12, 3.13) by listing them in the pyproject.toml and additionally adding tests for those version in the github actions.

Finally, version bumping for the imminent 0.59.2 release

[CPBridge]

@pieper any concerns?

[pieper]

Thanks for working on this! 👍