Bump django from 4.2.18 to 4.2.21

Bumps [django](https://github.com/django/django) from 4.2.18 to 4.2.21.
- [Commits](django/django@4.2.18...4.2.21)

---
updated-dependencies:
- dependency-name: django
  dependency-version: 4.2.21
  dependency-type: direct:production
...

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

Author: dependabot[bot]