dependency: (deps): bump django from 5.1.2 to 5.1.3 in /backend

Bumps [django](https://github.com/django/django) from 5.1.2 to 5.1.3.
- [Commits](django/django@5.1.2...5.1.3)

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

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

backend/requirements.txt

@@ -3,7 +3,7 @@ certifi==2024.8.30
 charset-normalizer==3.4.0
 coreapi==2.3.3
 coreschema==0.0.4
-Django==5.1.2
+Django==5.1.3
 django-cors-headers==4.6.0
 django-rest-swagger==2.2.0
 djangorestframework==3.15.2