Report manually marked single-threaded tests

[andfoy]

Fixes #46

This PR enables reporting tests that were marked as single-threaded using @pytest.mark.parallel_threads(1), as they were not being reported before

[lysnikolaou]

This looks good. Additionally, I think that the Some tests *not* run in parallel line appearing even if all tests were run in parallel is also a bug that should be fixed and which is why I opened #46 initially. For example, just running test_resolver.py gives me the following.

================================================================== test session starts ===================================================================
platform darwin -- Python 3.13.2+, pytest-8.3.5, pluggy-1.5.0
rootdir: /Users/lysnikolaou/repos/quansight/pyyaml
configfile: pyproject.toml
plugins: run-parallel-0.4.0
collected 3 items                                                                                                                                        
Collected 3 items to run in parallel

tests/free_threading/test_resolver.py ···                                                                                                          [100%]

************************************************************ Some tests *not* run in parallel ************************************************************
0 tests were not run in parallel because of use of thread-unsafe functionality, to list the tests that were skipped, re-run while setting PYTEST_RUN_PARALLEL_VERBOSE=1 in your shell environment
=================================================================== 3 passed in 0.77s ====================================================================

[andfoy]

Would we agree to rephrase it as thread-unsafe test report or something alongside those lines? Or should we omit the report altogether if there is nothing to report?

[lysnikolaou]

I'd be okay always showing. If all tests were run in parallel, then we could have something like this:

************************************************************ pytest-run-parallel report ************************************************************
All tests were run in parallel! 🎉 

[lysnikolaou]

Should we add a test for the new message if all tests were run in parallel?

[andfoy]

@lysnikolaou @ngoldbaum do you have any additional comments? Or should we merge this one?

[lysnikolaou]

LGTM!

[andfoy]

Let me produce a new release!