There are no breaking changes in 1.21.4.
- infra: updated Helm service account and RBAC objects to be kept when uninstalling Helm.
- web: fixed issue where users had to rebuild workspaces twice after regenerating SSH keys.
- infra: fixed race condition seen during the "starting networking agent" build step leading to a "context deadline exceeded" error message.
There are no security updates in 1.21.4.