Function update_machines_stats 

pub async fn update_machines_stats(
    config: Arc<Config>,
    dbus_cell: Arc<OnceCell<Connection>>,
    host_stats: Arc<RwLock<MachineStats>>,
    locked_monitord_stats: Arc<RwLock<MonitordStats>>,
    cached_connections: Arc<Mutex<MachineConnections>>,
) -> Result<()>