Bump gunicorn from 21.0.1 to 21.2.0

Bumps [gunicorn](https://github.com/benoitc/gunicorn) from 21.0.1 to 21.2.0.
- [Release notes](https://github.com/benoitc/gunicorn/releases)
- [Commits](benoitc/gunicorn@21.0.1...21.2.0)

---
updated-dependencies:
- dependency-name: gunicorn
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

requirements/base.txt

@@ -11,7 +11,7 @@ django-filter==23.2
 djangorestframework==3.14.0
 drf-spectacular==0.26.3
 drf-spectacular-sidecar==2023.7.1
-gunicorn==21.0.1
+gunicorn==21.2.0
 gviz_api==1.10.0
 psycopg2-binary==2.9.6
 pytz==2023.3