Update test/*.py files for PEP585 compliance.

[junkmd]

For the second step of #876, I chose the tests.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.70%. Comparing base (5fd01e3) to head (ef03f92).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #878   +/-   ##
=======================================
  Coverage   84.70%   84.70%           
=======================================
  Files         125      125           
  Lines       11536    11536           
=======================================
  Hits         9771     9771           
  Misses       1765     1765           

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