Upgrade Python version

[smartspot2]

The current Python version used in this repository is quite outdated; Python 3.9.13 was released in 2020, and 3.9.13 (released May 2022) was the last maintenance update for Python 3.9. The current latest 3.9 version is 3.9.18, with a bunch of security updates in between.

We should probably update the Python version to 3.11 or 3.12 to ensure that we continue getting the newest features and support from the latest packages. This upgrade may cause some dependency issues if any of our required dependencies have not added support for the later Python versions, though most should be updated to 3.11 now (3.12 may be more of an ask, since it's still quite new).

This is also a pretty good chance to update as many Python dependencies as we can, especially for security updates and other bugfix updates in any packages.