docs: remove cairo

[ccmao1130]

Cairo keeps throwing an error during local docs build even though it succeeds via Github Actions. Having trouble resolving even with https://squidfunk.github.io/mkdocs-material/plugins/requirements/image-processing/?h=cairo#cairo-library-was-not-found, so commenting out for now and can revisit later.

Context: Cairo is one of the packages that generates social previews for docs, ie:

We will lose social previews by disabling Cairo but social previews are not a priority for docs at the moment.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.45%. Comparing base (7bcec18) to head (6fc48f8).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3900   +/-   ##
=======================================
  Coverage   78.45%   78.45%           
=======================================
  Files         769      769           
  Lines       97732    97732           
=======================================
+ Hits        76678    76679    +1     
+ Misses      21054    21053    -1     

see 1 file with indirect coverage changes