Support for python 3.12

[FBruzzesi]

Description

Adds support for python 3.12

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the style guidelines (flake8)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (also to the readme.md)
• I have added tests that prove my fix is effective or that my feature works
• I have added tests to check whether the new feature adheres to the sklearn convention
• New and existing unit tests pass locally with my changes

[FBruzzesi]

importlib.resources.files is new in 3.9, importlib-resources is the backport

[koaning]

Maybe add a version bump so we can release a patch right away? Other than that, LGTM!

[koaning]

LGTM. I'll make the release right away, but lets not forget to market/tweet about it later this week.