Bump django from 2.2 to 2.2.28

Bumps [django](https://github.com/django/django) from 2.2 to 2.2.28.
- [Release notes](https://github.com/django/django/releases)
- [Commits](https://github.com/django/django/compare/2.2...2.2.28

)

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

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