Bump whitenoise from 6.5.0 to 6.6.0 in /backend

Bumps [whitenoise](https://github.com/evansd/whitenoise) from 6.5.0 to 6.6.0.
- [Changelog](https://github.com/evansd/whitenoise/blob/main/docs/changelog.rst)
- [Commits](evansd/whitenoise@6.5.0...6.6.0)

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

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

Author: dependabot[bot]

backend/requirements.txt

@@ -69,7 +69,7 @@ tzlocal==5.0.1
     # via apscheduler
 urllib3==2.0.6
     # via -r requirements.in
-whitenoise==6.5.0
+whitenoise==6.6.0
     # via -r requirements.in
 
 # The following packages are considered to be unsafe in a requirements file: