Bump whitenoise from 6.7.0 to 6.12.0 in /backend

Bumps [whitenoise](https://github.com/evansd/whitenoise) from 6.7.0 to 6.12.0.
- [Changelog](https://github.com/evansd/whitenoise/blob/main/docs/changelog.rst)
- [Commits](evansd/whitenoise@6.7.0...6.12.0)

---
updated-dependencies:
- dependency-name: whitenoise
  dependency-version: 6.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -53,7 +53,7 @@ dependencies = [
     "requests==2.34.0",
     "urllib3==2.7.0",
     "aniso8601==9.0.1",
-    "whitenoise==6.7.0",
+    "whitenoise==6.12.0",
     "django-ordered-model==3.5",
     "uwsgi==2.0.30",
     "django-storages==1.14.6",