Bump gunicorn from 20.1.0 to 22.0.0

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 20.1.0 to 22.0.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@20.1.0...22.0.0)

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

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

requirements.txt

@@ -3,7 +3,7 @@ Django>=3.2.10,<3.3
 wagtail==4.2.4
 dj-database-url>=1.0.0,<2.0
 psycopg2==2.9.3
-gunicorn==20.1.0
+gunicorn==22.0.0
 gevent==23.9.1
 django-dotenv==1.4.2
 django-google-optimize==0.3.0