chore(deps): bump django-celery-beat from 2.5.0 to 2.8.1

Bumps [django-celery-beat](https://github.com/celery/django-celery-beat) from 2.5.0 to 2.8.1.
- [Release notes](https://github.com/celery/django-celery-beat/releases)
- [Changelog](https://github.com/celery/django-celery-beat/blob/main/Changelog)
- [Commits](celery/django-celery-beat@v2.5.0...v2.8.1)

---
updated-dependencies:
- dependency-name: django-celery-beat
  dependency-version: 2.8.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

base-requirements.txt

@@ -20,7 +20,7 @@ beautifulsoup4==4.12.3
 icalendar==4.0.7
 chardet==4.0.0
 celery[redis]==5.4.0
-django-celery-beat==2.5.0
+django-celery-beat==2.8.1
 # TODO: We may drop 'django-imagekit' completely.
 django-imagekit==5.0  # 5.0 is first version that supports Django 4.2
 django-haystack==3.2.1