Bump django-environ from 0.8.1 to 0.9.0

Bumps [django-environ](https://github.com/joke2k/django-environ) from 0.8.1 to 0.9.0.
- [Release notes](https://github.com/joke2k/django-environ/releases)
- [Changelog](https://github.com/joke2k/django-environ/blob/main/CHANGELOG.rst)
- [Commits](joke2k/django-environ@v0.8.1...v0.9.0)

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

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

Author: dependabot[bot]

requirements/base.txt

@@ -1,5 +1,5 @@
 Django==3.2.14
-django-environ==0.8.1
+django-environ==0.9.0
 psycopg2==2.9.3
 djangorestframework==3.13.1