Drop support for Python 3.7 and add support for Python 3.12

[bih]

This is because Python 3.7 is no longer considered an active Python release and we currently only support up to Python 3.11 so we are 2 releases behind (3.12 and 3.13 but the latter being pre-release).

The current active releases are:

• 3.8
• 3.9
• 3.10
• 3.11
• 3.12

Python 3.8 will be no longer maintained (or considered an active release) as of October 2024, but we can move this to a separate discussion later in the year.