Update black requirement from ~=24.3 to ~=24.4 in /kerngen (#27)

Updates the requirements on [black](https://github.com/psf/black) to permit the latest version.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@24.3.0...24.4.2)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Michael Beale <[email protected]>

kerngen/requirements.txt

@@ -2,7 +2,7 @@
 pydantic ~= 1.10
 
 # for dev / commits
-black ~= 24.3
+black ~= 24.4
 pylint ~= 3.2
 
 # for testing