Fix 4227: Black does not print errors with --quiet --check

[dankrzeminski32]

Description

This closes #4227

black was previously not printing any information when called with the --quiet and --check flags.

the related issue makes a valid point that black should stay quiet on successful runs and notify the user when changes are found.

I've omitted part of the output in an attempt to keep the output still quiet, but I can add it in if desired.

For example, when called without the --quiet flag:

would reformat ../test_black/test.py

Oh no! 💥 💔 💥
1 file would be reformatted.

When called with the --quiet flag:

Oh no! 💥 💔 💥
1 file would be reformatted.

Checklist - did you ...

• Add an entry in CHANGES.md if necessary?
• Add / update tests if necessary?
• Add new / update outdated documentation?

[JelleZijlstra]

Thanks, but I think we don't need to change anything here (except perhaps the docs); see the issue.

[dankrzeminski32]

@JelleZijlstra Sounds good, I can make a small doc adjustment in this PR or create a new PR if desired.

[github-actions]

diff-shades reports zero changes comparing this PR (2ac51f4) to main (d1d4fc5).

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What is this? | Workflow run | diff-shades documentation

[JelleZijlstra]

Either works!