Support for Python 3.12

[joelaforet]

Hello! I would like to use this package in a workflow that depends on OpenFF-Pablo. Pablo is currently pinned to python >=3.12. Polymerist is pinned at python 3.11.

I did a quick pass at scoping what would need to change to bump Polymerist to 3.12 and found that this module would need to change:

https://github.com/timbernat/polymerist/blob/main/polymerist/genutils/importutils/pkginspect.py#L14

These functions: from importlib.resources._common import get_package, from_package, resolve are deprecated from the private API of importlib from version 3.12 onwards.

See these source files: old version | new version

Here is a link to their docs that details the updated pattern for users: https://docs.python.org/3.12/library/importlib.resources.html#importlib.resources

Public API's like: importlib.resources.files() and/or importlib.util.find_spec() may be useful.

Happy to open a PR if man-power is needed to address this!

[joelaforet]

As a heads up to bump this issue, OpenFF Interchange is now deprecating support for Python 3.11 (here) to be compliant with SPEC 0000. Many other projects in the OSS ecosystem are likely to make this change too.