Py-pde

Fix critical bug where version was not determined correctly

Completely revamped the build system to be more compact, flexible, and future proof

Switched from `versioneer` to `setuptools_scm`

This release switched the setup routine by introducing [versioneer](https://github.com/python-versioneer/python-versioneer). Consequently, the tags will now not contain the (superfluous) `v` anymore.

What's Changed
* Improved typing by david-zwicker in https://github.com/zwicker-group/py-pde/pull/335
* Allow easier splitting of fields onto MPI nodes by david-zwicker in https://github.com/zwicker-group/py-pde/pull/337
* Switched to `pyproject.toml` configuration file by david-zwicker in https://github.com/zwicker-group/py-pde/pull/338


**Full Changelog**: https://github.com/zwicker-group/py-pde/compare/v0.23.0...0.24.0