Use pytest everywhere

[joanise]

See EveryVoiceTTS/EveryVoice#792

[semanticdiff-com]

Review changes with  

Changed Files

File	Status
fs2/tests/test_writing_callbacks.py	95% smaller
fs2/tests/test_cli.py	93% smaller
fs2/tests/test_loading.py	91% smaller
fs2/tests/test_chunking.py	76% smaller
.coveragerc	Unsupported file format
.github/workflows/test.yml	0% smaller
fs2/run_tests.py	0% smaller

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 47.88%. Comparing base (8f1f4ea) to head (5840db6).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #138      +/-   ##
==========================================
- Coverage   49.69%   47.88%   -1.82%     
==========================================
  Files          27       27              
  Lines        1988     1988              
  Branches        0      225     +225     
==========================================
- Hits          988      952      -36     
  Misses       1000     1000              
- Partials        0       36      +36     

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[joanise]

Coverage went down because I enabled branch coverage. If you count Hits+Partials how, you get what we had for Hits before.

[roedoejet]

lgtm