Bump whitenoise from 6.7.0 to 6.8.1

Bumps [whitenoise](https://github.com/evansd/whitenoise) from 6.7.0 to 6.8.1.
- [Changelog](https://github.com/evansd/whitenoise/blob/main/docs/changelog.rst)
- [Commits](evansd/whitenoise@6.7.0...6.8.1)

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

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

requirements/base.txt

@@ -21,7 +21,7 @@ djangorestframework==3.15.2  # https://github.com/encode/django-rest-framework
 
 # Web serving
 gunicorn==22.0.0
-whitenoise==6.7.0
+whitenoise==6.8.1
 
 # Database APIs
 psycopg2==2.9.10