dependency: (deps): bump django-cors-headers in /backend

Bumps [django-cors-headers](https://github.com/adamchainz/django-cors-headers) from 4.3.1 to 4.4.0.
- [Changelog](https://github.com/adamchainz/django-cors-headers/blob/main/CHANGELOG.rst)
- [Commits](adamchainz/django-cors-headers@4.3.1...4.4.0)

---
updated-dependencies:
- dependency-name: django-cors-headers
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/requirements.txt

@@ -4,7 +4,7 @@ charset-normalizer==3.3.2
 coreapi==2.3.3
 coreschema==0.0.4
 Django==5.1
-django-cors-headers==4.3.1
+django-cors-headers==4.4.0
 django-rest-swagger==2.2.0
 djangorestframework==3.15.2
 drf-yasg==1.21.7