Notice: PyQt & Python Version Changes for PyMOL 3.2

[JarrettSJohnson]

This probably wouldn't be suitable for a Github issue, but I just wanted to give a heads up on the following related PyQt and Python version changes since that may affect some plugins and scripts

For PyMOL 3.2:

• Qt5 is past end-of-support, and as such we'll strictly support PyQt6/PySide6 only
• Python 3.9 is approaching end-of-life in October, and as such we will be dropping support
• Python 3.13 support will be added.
• We're continuing to phase out support for Tkinter plugins and request to use python Qt instead. I've migrated several plugins already and intend to submit PRs for including them here.

We're currently shooting for a mid September release.