8.22.0
You can see the changelog for upstream sentry versions 8.21.0 and 8.22.0.
We rolled our production instance from 8.20 to 8.22 without a hitch.
To upgrade, just run
docker-compose stop sentry-web sentry-worker sentry-cron
docker-compose run --rm sentry-web sentry upgrade
docker-compose up -d
Additional upgrade note
If upgrading from 8.20 or lower, your next visit to your sentry instance you'll be prompted to opt in / out of their anonymous data collection service.