Bump django from 4.2.20 to 4.2.21 in /requirements

Bumps [django](https://github.com/django/django) from 4.2.20 to 4.2.21.
- [Commits](django/django@4.2.20...4.2.21)

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

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

Author: dependabot[bot]

requirements/base.txt

@@ -1,5 +1,5 @@
 asgiref==3.8.1
-Django==4.2.20
+Django==4.2.21
 pytz==2025.2
 requests==2.32.3
 sqlparse==0.5.3