Simplify tests with T.TempDir

[alexandear]

Describe the change

The PR refactors tests that contain os.MkdirTemp and os.Remove with T.TempDir. That allows to remove 50 lines of test code without harming readability.
Also, enables usetesting to automatically detect this in the future.

Describe your solution

The PR replaces usages of CreateTestDirectory with t.TempDir(). It's not needed to call os.Remove anymore.

Additional context

TempDir returns a temporary directory for the test to use. The directory is automatically removed when the test and all its subtests complete.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.69%. Comparing base (774fc9d) to head (04e8437).
Report is 79 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #929      +/-   ##
==========================================
+ Coverage   98.46%   98.69%   +0.23%     
==========================================
  Files          24       26       +2     
  Lines        1364     1761     +397     
==========================================
+ Hits         1343     1738     +395     
- Misses         15       16       +1     
- Partials        6        7       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[sashabaranov]

Great work, thank you so much!