Bump django-environ from 0.11.2 to 0.12.0

Bumps [django-environ](https://github.com/joke2k/django-environ) from 0.11.2 to 0.12.0.
- [Release notes](https://github.com/joke2k/django-environ/releases)
- [Changelog](https://github.com/joke2k/django-environ/blob/main/CHANGELOG.rst)
- [Commits](https://github.com/joke2k/django-environ/commits)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements/base.txt

@@ -1,6 +1,6 @@
 # Django
 django==3.2.25
-django-environ==0.11.2
+django-environ==0.12.0
 django-model-utils==4.5.1
 django-anymail[mailgun]==9.2
 django-mail-templated==2.6.5