removing irrelevant cmake tests

[K20shores]

I feel like these tests don't do anything for us and we should remove them. What do y'all think? We inherently test that we can use fetch content by using it in musica

[mattldawson]

fine by me!

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.25%. Comparing base (555be4e) to head (3cc3af2).
Report is 8 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #556   +/-   ##
=======================================
  Coverage   92.25%   92.25%           
=======================================
  Files          45       45           
  Lines        3407     3407           
=======================================
  Hits         3143     3143           
  Misses        264      264           

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