Celery 4.4 development branch got another release with the following improvements:

- Kombu 4.6.7

- Events bootstep disabled if no events (#5807)

- SQS - Reject on failure (#5843)

- Add a concurrency model with ThreadPoolExecutor (#5099)

- Add auto expiry for DynamoDB backend (#5805)

- Store extending result in all backends (#5661)

- Fix a race condition when publishing a very large chord header (#5850)

- Improve docs and test matrix

Please test the release and report issues.