Bump django in /examples/server/wsgi/django_socketio

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] <support@github.com>

Author: dependabot[bot]

examples/server/wsgi/django_socketio/requirements.txt

@@ -1,6 +1,6 @@
 asgiref==3.6.0
 bidict==0.22.1
-Django==4.2.20
+Django==4.2.21
 gunicorn==23.0.0
 h11==0.16.0
 python-engineio