Bump djangorestframework from 3.15.1 to 3.15.2 in /requirements

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.15.1 to 3.15.2.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](encode/django-rest-framework@3.15.1...3.15.2)

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

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

requirements/main.txt

@@ -10,7 +10,7 @@ django-searchable-encrypted-fields==0.2.1
 django-silk==5.1.0
 django-solo==2.2.0
 django-url-or-relative-url-field==0.2.0
-djangorestframework==3.15.1
+djangorestframework==3.15.2
 djangorestframework-api-key==3.0.0
 docutils==0.21.2
 drf-yasg==1.21.7