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.

We do this by checking if new IDs that were allocated after the preflight check began were committed to the catalog.