Bump djangorestframework from 3.11.0 to 3.15.2 in /src

Bumps [djangorestframework](https://github.com/encode/django-rest-framework) from 3.11.0 to 3.15.2.
- [Release notes](https://github.com/encode/django-rest-framework/releases)
- [Commits](encode/django-rest-framework@3.11.0...3.15.2)

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

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

src/requirements.txt

@@ -2,7 +2,7 @@ celery==4.4.7
 dj-database-url==0.5.0
 Django==3.0.2
 django-filter==2.2.0
-djangorestframework==3.11.0
+djangorestframework==3.15.2
 jsonfield2==3.1.0
 redis==3.3.11
 regex==2022.4.24