Use 3.12 for formatting check

[A5rocks]

Fixes #2681. Not using the lowest version means:

• this runs faster because Python is faster now
• it's clear that this doesn't need to be the lowest supported version.

This works now because of the switch to uv which has a --python-version flag.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.63%. Comparing base (20f9291) to head (f11f044).
Report is 176 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3049   +/-   ##
=======================================
  Coverage   99.63%   99.63%           
=======================================
  Files         120      120           
  Lines       17832    17832           
  Branches     3204     3204           
=======================================
  Hits        17767    17767           
  Misses         46       46           
  Partials       19       19           

[CoolCat467]

Looks good provided that the CI succeeds

[CoolCat467]

Shouldn't we also update no test-requirements while we are at it?

[A5rocks]

Shouldn't we also update no test-requirements while we are at it?

I think its python version isn't related to the formatting check. (and it can be upgraded whenever, I forgot the motivation behind it...)

Actually, it's probably better to be < 3.11 because otherwise ExceptionGroup is built in.