Bump django-celery-results from 2.3.1 to 2.4.0

Bumps [django-celery-results](https://github.com/celery/django-celery-results) from 2.3.1 to 2.4.0.
- [Release notes](https://github.com/celery/django-celery-results/releases)
- [Changelog](https://github.com/celery/django-celery-results/blob/master/Changelog)
- [Commits](https://github.com/celery/django-celery-results/compare/v2.3.1...v2.4.0

)

---
updated-dependencies:
- dependency-name: django-celery-results
  dependency-type: direct:production
...

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