ci: make pre-commit check pass

[cakebaker]

This PR makes three changes to make the pre-commit check in the CI pass:

• make util/test_compare_test_results.py executable
• remove trailing whitespace
• add newlines at the end of files

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.20%. Comparing base (f783eb9) to head (f2871d2).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #418   +/-   ##
=======================================
  Coverage   82.20%   82.20%           
=======================================
  Files          13       13           
  Lines        5542     5542           
  Branches      310      310           
=======================================
  Hits         4556     4556           
  Misses        983      983           
  Partials        3        3           

Flag	Coverage Δ
macos_latest	82.89% <ø> (ø)
ubuntu_latest	82.99% <ø> (ø)
windows_latest	0.00% <ø> (ø)

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