Update to remove pkg_resources

[wouterdb]

Hi,

Thank you for building this very useful library.

Because pkg_resources is deprecated and removed in Python 3.12, we needed an update of the library.
We have implemented this at inmanta/inmanta-core#9246.

This PR backports our changes:

1. Remove pkg_resources
2. Add mypy types
3. Move testing to native pytest
4. Drop support for python versions <3.12

I hope this can get merged and released.

Wouter

[abbasyadollahi]

given there's been no activity in 7 years, I think this project might be dead :(
@omergertel would be great if we can get this merged in, or if there's any chance of opening up this project so it can be maintained by the community