feat: upgrade to Pest v4 and implement testing improvements

[KilianTrunk]

No description provided.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 19.94%. Comparing base (9ca719c) to head (13bd61a).

Additional details and impacted files

@@              Coverage Diff              @@
##               main      #23       +/-   ##
=============================================
- Coverage     83.27%   19.94%   -63.34%     
  Complexity      260      260               
=============================================
  Files            31       31               
  Lines          1369     1369               
=============================================
- Hits           1140      273      -867     
- Misses          229     1096      +867     

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[KilianTrunk]

@SlimDeluxe check the test names - sharding should be self-explanatory, but its basically splitting up tests into batches