chore(deps): bump django in /backend in the python group (#630)

Bumps the python group in /backend with 1 update: [django](https://github.com/django/django).


Updates `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
  dependency-group: python
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

backend/requirements.txt

@@ -12,7 +12,7 @@ beautifulsoup4==4.12.3
     # via -r requirements.in
 dj-database-url==2.3.0
     # via -r requirements.in
-django==5.1.2
+django==5.1.3
     # via
     #   -r requirements.in
     #   dj-database-url