Bump django from 4.2.18 to 4.2.20 in /requirements

Bumps [django](https://github.com/django/django) from 4.2.18 to 4.2.20.
- [Commits](django/django@4.2.18...4.2.20)

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

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

Author: dependabot[bot]

Diff for: requirements/common.txt

@@ -3,7 +3,7 @@
 dj-database-url==2.2.0
 
 # This is a Django app
-Django==4.2.18
+Django==4.2.20
 
 # A zero dependency WSGI server
 gunicorn==22.0.0