build(deps): bump djangorestframework from 3.14.0 to 3.15.2

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.14.0 to 3.15.2.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](encode/django-rest-framework@3.14.0...3.15.2)

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

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

requirements.txt

@@ -74,7 +74,7 @@ django-invitations<2.1.1
 django-recaptcha==4.0.0
 
 # REST
-djangorestframework==3.14.0
+djangorestframework==3.15.2
 djangorestframework-gis==1.0
 djangorestframework-guardian==0.3.0
 drf-extensions==0.7.1