add xdist, auto, group by test file

[psobolewskiPhD]

References and relevant issues

Description

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

❌ Patch coverage is 11.11111% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 41.80%. Comparing base (6da9831) to head (31b656c).

Files with missing lines	Patch %	Lines
src/napari/conftest.py	16.66%	5 Missing ⚠️
src/napari/_qt/_tests/test_app.py	0.00%	2 Missing ⚠️
src/napari/_tests/test_viewer.py	0.00%	1 Missing ⚠️
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff             @@
##             main      #61       +/-   ##
===========================================
- Coverage   92.95%   41.80%   -51.16%     
===========================================
  Files         711      598      -113     
  Lines       64070    49767    -14303     
===========================================
- Hits        59558    20804    -38754     
- Misses       4512    28963    +24451     

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.