TEST: Get tests working

[effigies]

There's stuff that's really specific to GitHub actions here, and I don't think it's necessary. This gets things working on my machine. If the things I've removed serve a useful purpose on your machine, we can re-add them separately, making sure they don't break anything.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 31.75%. Comparing base (774e0e2) to head (0dc05b3).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #27      +/-   ##
==========================================
- Coverage   33.64%   31.75%   -1.89%     
==========================================
  Files          25       24       -1     
  Lines        2060     2028      -32     
  Branches      303      298       -5     
==========================================
- Hits          693      644      -49     
- Misses       1344     1374      +30     
+ Partials       23       10      -13     

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