Bump django from 2.2.27 to 2.2.28

Bumps [django](https://github.com/django/django) from 2.2.27 to 2.2.28.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.2.27...2.2.28)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]