Fix doc build issues

[bsipocz]

Currently, there are 12 warnings during building the docs, and it's not exactly clear why they don't make the build fail, as -W is being used both in the actions/tox based run, and in rtd.

First I try to make the build fail, then will push all the fix commits.

[codecov]

Codecov Report

Merging #2226 (cb12f86) into main (cbec82e) will increase coverage by 0.15%.
The diff coverage is n/a.

❗ Current head cb12f86 differs from pull request most recent head d46a111. Consider uploading reports for the commit d46a111 to get more accurate results

@@            Coverage Diff             @@
##             main    #2226      +/-   ##
==========================================
+ Coverage   61.81%   61.96%   +0.15%     
==========================================
  Files         129      129              
  Lines       16295    16297       +2     
==========================================
+ Hits        10072    10099      +27     
+ Misses       6223     6198      -25     

Impacted Files	Coverage Δ
astroquery/conftest.py	92.30% <0.00%> (+0.64%)	⬆️
astroquery/alma/core.py	41.35% <0.00%> (+4.69%)	⬆️

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[bsipocz]

The warnings are cleared, hopefully, the renaming of the config file will be then enough so it will be picked up by RTD once it's on the main branch.