Fix hang in editor completion unit test

crates/editor/src/editor.rs

@@ -6826,6 +6826,7 @@ mod tests {
             .with_language_server(language_server, cx)
         });
         let buffer = cx.add_model(|cx| MultiBuffer::singleton(buffer, cx));
+        buffer.next_notification(&cx).await;
 
         let (_, editor) = cx.add_window(|cx| build_editor(buffer, settings, cx));
 
@@ -6881,6 +6882,7 @@ mod tests {
             );
             apply_additional_edits
         });
+
         let (id, _) = fake
             .receive_request::<lsp::request::ResolveCompletionItem>()
             .await;

crates/language/src/buffer.rs

@@ -746,6 +746,7 @@ impl Buffer {
                                         Operation::UpdateCompletionTriggers { triggers },
                                         cx,
                                     );
+                                    cx.notify();
                                 });
                             } else {
                                 return;