Bump django-prometheus from 2.2.0 to 2.3.1

Bumps [django-prometheus](https://github.com/korfuri/django-prometheus) from 2.2.0 to 2.3.1.
- [Release notes](https://github.com/korfuri/django-prometheus/releases)
- [Changelog](https://github.com/korfuri/django-prometheus/blob/master/CHANGELOG.md)
- [Commits](django-commons/django-prometheus@v2.2.0...v2.3.1)

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

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

Author: dependabot[bot]

Pipfile

@@ -78,7 +78,7 @@ django-fakery = "==3.0.0"
 djangorestframework-jwt = "==1.11.0"
 jsonfield = "==2.0.2"
 azure-search-documents = "==11.3.0"
-django-prometheus = "==2.2.0"
+django-prometheus = "==2.3.1"
 
 [requires]
 python_version = "3.8"