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

@@ -10,7 +10,7 @@ djangorestframework>=3.13.1,<4
 djangorestframework-guardian==0.3.0
 django-reversion==5.0.1
 drf-yasg>=1.21.4,<2
-gunicorn==20.1.0
+gunicorn==22.0.0
 psycopg2-binary==2.9.3
 PyGithub==1.55
 rdflib==6.1.1