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] <support@github.com>

requirements.txt

@@ -25,7 +25,7 @@ django-debug-toolbar==4.0.0
 django-js-asset==2.0.0
 django-redis==5.2.0
 django-social-share==2.3.0
-gunicorn==20.1.0
+gunicorn==22.0.0
 idna==3.7
 kombu==5.2.4
 Markdown==3.4.1