Bump django from 4.2.19 to 5.1.6 in /requirements

Bumps [django](https://github.com/django/django) from 4.2.19 to 5.1.6.
- [Commits](django/django@4.2.19...5.1.6)

---
updated-dependencies:
- dependency-name: django
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]