gh-89392: Remove test_main() in test_netrc

[serhiy-storchaka]

• Issue: Always use unittest for collecting tests in regrtests #89392

[miss-islington]

Thanks @serhiy-storchaka for the PR 🌮🎉.. I'm working now to backport this PR to: 3.11, 3.12.
🐍🍒⛏🤖 I'm not a witch! I'm not a witch!

[miss-islington]

Sorry, @serhiy-storchaka, I could not cleanly backport this to 3.12 due to a conflict.
Please backport using cherry_picker on command line.
cherry_picker 76f3c043b6c5971d5a13fc6decf87a80ddf7ef95 3.12

[bedevere-bot]

GH-108868 is a backport of this pull request to the 3.11 branch.

[bedevere-bot]

GH-108872 is a backport of this pull request to the 3.12 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Windows10 3.12 has failed when building commit 88ff02e.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/1159/builds/304) and take a look at the build logs.
4. Check if the failure is related to this commit (88ff02e) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/1159/builds/304

Failed tests:

• test.test_concurrent_futures.test_shutdown
• test.test_concurrent_futures.test_process_pool

Failed subtests:

• test_map_timeout - test.test_concurrent_futures.test_process_pool.ProcessPoolSpawnProcessPoolExecutorTest.test_map_timeout

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 480, in temp_dir
    yield path
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 533, in temp_cwd
    yield cwd_dir
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\libregrtest\main.py", line 795, in main
    self._main(tests, kwargs)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\libregrtest\main.py", line 854, in _main
    sys.exit(0)
SystemExit: 0


Traceback (most recent call last):
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\test_concurrent_futures\executor.py", line 68, in test_map_timeout
    self.assertEqual([None, None], results)
AssertionError: Lists differ: [None, None] != []


Traceback (most recent call last):
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\runpy.py", line 198, in _run_module_as_main
    return _run_code(code, main_globals, None,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\runpy.py", line 88, in _run_code
    exec(code, run_globals)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\__main__.py", line 2, in <module>
    main()
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\libregrtest\main.py", line 859, in main
    Regrtest().main(tests=tests, **kwargs)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\libregrtest\main.py", line 789, in main
    with os_helper.temp_cwd(test_cwd, quiet=True):
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\contextlib.py", line 155, in __exit__
    self.gen.throw(value)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 531, in temp_cwd
    with temp_dir(path=name, quiet=quiet) as temp_path:
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\contextlib.py", line 155, in __exit__
    self.gen.throw(value)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 485, in temp_dir
    rmtree(path)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 442, in rmtree
    _rmtree(path)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 385, in _rmtree
    _waitfor(_rmtree_inner, path, waitall=True)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 330, in _waitfor
    func(pathname)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\os_helper.py", line 382, in _rmtree_inner
    _force_run(fullname, os.rmdir, fullname)
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\__init__.py", line 218, in _force_run
    return func(*args)
           ^^^^^^^^^^^
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'D:\\buildarea\\3.12.bolen-windows10\\build\\build\\test_python_2696�\\test_python_worker_5284�'


Traceback (most recent call last):
  File "D:\buildarea\3.12.bolen-windows10\build\Lib\test\support\__init__.py", line 207, in _force_run
    return func(*args)
           ^^^^^^^^^^^
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'D:\\buildarea\\3.12.bolen-windows10\\build\\build\\test_python_2696�\\test_python_worker_5284�'