Update black requirement from ~=25.1.0 to ~=25.9.0

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@25.1.0...25.9.0)

---
updated-dependencies:
- dependency-name: black
  dependency-version: 25.9.0
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
-black~=25.1.0
+black~=25.9.0
 csh_ldap @ git+https://github.com/ComputerScienceHouse/csh_ldap@2.5.0
 flask==3.1.2
 jinja2==3.1.6