Add Upgrade Support for Main Cluster + Standby Cluster

[vitabaks]

Currently, after updating the main cluster, it is necessary to deploy a new standby cluster. While this approach works, it is not convenient, especially for large databases, as it requires substantial time and computing resources.

Proposal:
Add support for upgrading the standby cluster so it can be updated alongside the main cluster. This enhancement would streamline the upgrade process for larger clusters, making it more efficient and less time-consuming.