Remove markers from fixtures, pytest errors now

[maxnoe]

Adding markers to fixtures never worked, but was silently ignored until now.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.92%. Comparing base (fa75248) to head (1ae21d4).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1394      +/-   ##
==========================================
- Coverage   84.93%   84.92%   -0.02%     
==========================================
  Files          94       94              
  Lines        9495     9487       -8     
==========================================
- Hits         8065     8057       -8     
  Misses       1430     1430              

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