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

Bumps [django-cors-headers](https://github.com/adamchainz/django-cors-headers) from 4.4.0 to 4.6.0.
- [Changelog](https://github.com/adamchainz/django-cors-headers/blob/main/CHANGELOG.rst)
- [Commits](adamchainz/django-cors-headers@4.4.0...4.6.0)

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

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

backend/requirements/base.txt

@@ -17,6 +17,6 @@ djangorestframework-simplejwt==5.3.1    # https://github.com/jazzband/djangorest
 django-health-check==3.18.3             # https://github.com/revsys/django-health-check
 django-environ==0.11.2                  # https://github.com/joke2k/django-environ
 django-celery-beat==2.7.0               # https://github.com/celery/django-celery-beat
-django-cors-headers==4.4.0              # https://github.com/adamchainz/django-cors-headers
+django-cors-headers==4.6.0              # https://github.com/adamchainz/django-cors-headers
 djangorestframework-api-key==3.0.0      # 
 jinja2==3.1.4                           # https://github.com/pallets/jinja/