Bump black from 21.4b2 to 24.3.0 in /requirements

Bumps [black](https://github.com/psf/black) from 21.4b2 to 24.3.0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](https://github.com/psf/black/commits/24.3.0)

---
updated-dependencies:
- dependency-name: black
  dependency-type: direct:production
...

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

requirements/test.txt

@@ -2,7 +2,7 @@
 attrs~=21.2.0
 cfgv~=3.3.0
 blinker~=1.4
-black==21.4b2
+black==24.3.0
 isort~=5.10.1
 jsonref~=0.2
 pytest~=7.1.1