Bump celery from 4.4.7 to 5.3.6

Bumps [celery](https://github.com/celery/celery) from 4.4.7 to 5.3.6.
- [Release notes](https://github.com/celery/celery/releases)
- [Changelog](https://github.com/celery/celery/blob/main/Changelog.rst)
- [Commits](celery/celery@v4.4.7...v5.3.6)

---
updated-dependencies:
- dependency-name: celery
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

requirements/base.txt

@@ -34,7 +34,7 @@ django-autoslug==1.9.8
 pytz==2021.1
 
 # Celery support
-celery==4.4.7
+celery==5.3.6
 
 # Redis support
 django-redis==4.11.0