Description: Mimir 6.0 ships a new version of the rollout-operator that introduces breaking schema changes to the ReplicaTemplate and ZoneAwarePodDisruptionBudget CRDs. Helm cannot apply updated CRDs over existing ones with incompatible schemas, so a pre-upgrade hook job must delete the old CRD definitions before Helm applies the new ones. Without this, upgrades from any 5.x release will fail at the CRD apply step. Acceptance Criteria: - [x] Pre-upgrade hook job runs before CRD resources are applied - [x] Upgrade from 5.x to 6.0.6 completes without CRD conflict errors - [x] Job cleans up after completion