Increase pytest verbosity

[radarhere]

In discussing the difference between pytest -v and pytest -vv with regards to checking iOS wheels, @freakboy3742 said

In case of success, there's no real difference; but in case of failure, -vv will sometimes include failure context (such as complete diffs) that is truncated by -v. If we can put the full context in the logs, why not do so?

I'm interested in consistency, so if that argument holds for testing iOS wheels, then why not everywhere else as well?

You can read about the effect at https://docs.pytest.org/en/stable/how-to/output.html#verbosity

[radarhere]

I've pushed a commit to exit early on test failure in wheel tests - which we're already doing in some wheels that use wheels-test.ps1.

Pillow/.github/workflows/wheels-test.ps1

Lines 26 to 28 in e783aff

	& $venv\Scripts\$python -m pytest -vx Tests\check_wheel.py
	if (!$?) { exit $LASTEXITCODE }
	& $venv\Scripts\$python -m pytest -vx Tests