Bump black from 24.4.2 to 24.8.0

Bumps [black](https://github.com/psf/black) from 24.4.2 to 24.8.0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@24.4.2...24.8.0)

---
updated-dependencies:
- dependency-name: black
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements.txt

@@ -1,4 +1,4 @@
-black == 24.4.2
+black == 24.8.0
 briefcase @ git+https://github.com/beeware/briefcase.git
 flake8 == 7.1.0
 pre-commit == 3.8.0