Chore: Python 2 deprecation in lib

[iLLiCiTiT]

Changelog Description

Remove Python 2 compatibility from functions in ayon_core.lib.

Additional info

Classes do no inherit from object. Simplified doubled imports for Py2 and Py3 compatibility of configparser and lru_cache. Use WeakMethod directly from weakref and warn on import of python_2_comp.py.

Testing notes:

1. Go through code and check possible errors I made.
2. Validate everything is working as expected.

[BigRoy]

• Tray works
• Tray loader works
• Launcher works
• Maya 2024 works, incl. workfiles, publishing, loading and managing
• Fusion 18 works, incl. workfiles, publishing, loading and managing

Code seems fine.

Remove python_2_comp.py file now

I have my doubts about whether it's really worth it to have backwards compatibility for python_2_comp. I can't find any usage across the codebases and I wonder if anyone would've ever touched it at all. And even if they would - their logic wouldn't be valid for Py3 anyway. So I'd personally opt for removing python_2_comp.py completely.

@iLLiCiTiT

[iLLiCiTiT]

Remove python_2_comp.py file now

We have to be somewhat careful about breaking backwards compatibility. I can't know if there is an addon that is using it, having it there with warning for some time won't hurt.

their logic wouldn't be valid for Py3 anyway

It would be Py3 valid. The content was Py2 and Py3 compatible, you could import it to support both.

Note, start filename with underscore if should not be imported publicly.