dependency: (deps): bump djangorestframework in /backend

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] <[email protected]>

backend/requirements.txt

@@ -14,7 +14,7 @@ distro==1.9.0
 Django==5.0.6
 django-cors-headers==4.3.1
 django-rest-framework==0.1.0
-djangorestframework==3.15.1
+djangorestframework==3.15.2
 djangorestframework-simplejwt==5.3.1
 dnspython==2.6.1
 python-docx==1.1.2