Function check_ddl_changes

async fn check_ddl_changes(
    boot_ts: Timestamp,
    persist_client: PersistClient,
    environment_id: EnvironmentId,
    deploy_generation: u64,
    catalog_metrics: Arc<Metrics>,
    bootstrap_args: BootstrapArgs,
    initial_next_user_item_id: u64,
    initial_next_replica_id: u64,
)

Check if there have been any DDL that create new collections or replicas, restart in read-only mode if so, in order to pick up those new items and start hydrating them before cutting over.