- Added a heartbeat function to renew the Redis lock during database migrations, preventing long blockages from crashed processes.
- Updated the upgrade_db command to utilize the new locking mechanism with a configurable TTL.
- Removed the deprecated MIGRATION_LOCK_TTL from DeploymentConfig and related files.
- Enhanced unit tests to cover the new lock renewal behavior and error handling during migrations.
(cherry picked from commit a3331c622435f9f215b95f6b0261f43ae56a9d9c)