Make coordinator's `start_inner` function `Send` again

The name generator uses a thread-local random number generator internally, which makes it `!Send`. So we should not keep it across await points because our `multiple_daemons` example needs to spawn it in the tokio runtime, which requires `Send`.

binaries/coordinator/src/lib.rs

@@ -159,8 +159,6 @@ async fn start_inner(
     let mut archived_dataflows: HashMap<Uuid, ArchivedDataflow> = HashMap::new();
     let mut daemon_connections: HashMap<_, DaemonConnection> = HashMap::new();
 
-    let mut name_generator = names::Generator::default();
-
     while let Some(event) = events.next().await {
         if event.log() {
             tracing::trace!("Handling event {event:?}");
@@ -305,7 +303,7 @@ async fn start_inner(
                             name,
                             local_working_dir,
                         } => {
-                            let name = name.or_else(|| name_generator.next());
+                            let name = name.or_else(|| names::Generator::default().next());
 
                             let inner = async {
                                 if let Some(name) = name.as_deref() {