[FEATURE] Enable pandapower tests for Python 3.13

[mgovers]

In #305 we had to disable some checks so that we could enable CI checks on Python 3.13. This PR reverts that, probably after pandapower 3.1 is released.

Requires pandapower to be compatible with a scipy version that is compatible with python 3.13.

• Remove the dependency group dev-bare and do everything in dev again in the pyproject.toml
• Re-combine the logic in the build-test-release.yml CI workflow for Python 3.11/12 and Python 3.13
• Re-add PandaPowerConverter to the code coverage
• Remove the importskip("pandapower") logic
• Re-set the minimal coverage requirement --cov-fail-under

Relates to #289