Fix docs building and docs

[janfb]

• fix CD
• update docs building docs.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.86%. Comparing base (8ee2a2c) to head (3eb1379).
Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1217   +/-   ##
=======================================
  Coverage   84.86%   84.86%           
=======================================
  Files          97       97           
  Lines        7677     7677           
=======================================
  Hits         6515     6515           
  Misses       1162     1162           

Flag	Coverage Δ
unittests	84.86% <ø> (ø)

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