build(deps): bump django from 3.1.8 to 3.1.12

Bumps [django](https://github.com/django/django) from 3.1.8 to 3.1.12.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@3.1.8...3.1.12)

---
updated-dependencies:
- dependency-name: django
  dependency-type: direct:production
...

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

requirements.txt

@@ -1,5 +1,5 @@
 dj-database-url==0.5.0
-Django==3.1.8
+Django==3.1.12
 django-allauth==0.44.0
 django-anymail==8.2
 django-cors-headers==3.7.0