ci: Split 'all' into smaller tasks

[pdgendt]

Run testing on the different supported versions while running the linter and type checks only on 1 combination.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.52%. Comparing base (ba70229) to head (48c4435).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #858   +/-   ##
=======================================
  Coverage   84.52%   84.52%           
=======================================
  Files          11       11           
  Lines        3366     3366           
=======================================
  Hits         2845     2845           
  Misses        521      521           

[marc-hb]

I find the ways to extend GH matrices super obtuse; I have to go back to the docs every time. Can you please use comment(s) to warn the reader about that? I mean this is one of those rare cases where readers are deceived into thinking "How hard to understand could this simple syntax be? I really don't need to spend time finding the documentation".

But yes they do. Otherwise they waste a lot more time.

• It's really not intuitive that include extends!
• It's not intuitive either that test does not get overwritten and still runs for 3.13.

So please mention these, and also strongly recommend to open the documentation. It's currently at
https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#example-adding-configurations but maybe just the section name in the doc is more "permanent" and enough.

Otherwise everything looks good.

[pdgendt]

Added a comment with a link to the docs