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>

Author: dependabot[bot]

requirements.txt

@@ -36,7 +36,7 @@ django-webpack-loader==1.8.1
 djangorestframework==3.12.4
 freezegun==1.1.0
 geonamescache==1.3.0
-gunicorn==20.1.0
+gunicorn==22.0.0
 h11==0.12.0
 icalendar==4.0.9
 idna==3.3