Add support for Python 3.13 and remove Python 3.8

[dpgraham4401]

Description

This PR adds support for Python version 3.13, removes support for Python 3.8 (which has reached EOL). It also updates the ruff version to the latest version (0.9.9) and the targeted python lint/formatting version to 3.9. Targeting 3.9+ allows us to use built-in collection types such as list and dict as generic types instead of importing the corresponding capitalized types (e.g. List or Dict) from typing.