Drop breaking sphinx docs build

[ethanwharris]

What does this PR do?

Sphinx build CI is breaking and couldn't find a fix. Not needed anyway as docs build is covered by the other CI and pre-commit

Does your PR introduce any breaking changes? If yes, please list them.

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[codecov]

Codecov Report

Merging #8934 (4ac5edf) into master (d0efb55) will decrease coverage by 4%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #8934    +/-   ##
=======================================
- Coverage      93%     89%    -4%     
=======================================
  Files         172     172            
  Lines       14093   14093            
=======================================
- Hits        13095   12516   -579     
- Misses        998    1577   +579     

[awaelchli]

adding 1.4.x label so we don't forget to include it in the bugfix branch too :)

[daniellepintz]

this is awesome! next, can we either fix or delete the TPU tests to get closer to a green CI? cc @Borda