Python Bindings: Increment minimal required Python version to 3.10

[rcrdnalor]

• Platform: all

• MythTV version: mythtv v36-pre

• Package version: N/A

• Component: Python Bindings

What is the expected behaviour?

MythTVs implementation of the datetime class should only use time-zones defined by the ZoneInfo module,
which is part of the Python distribution (since Python 3.9).
The hand crafted implementation of time-zones (posixtzinfo) and its usage should be removed.