chore: Fix hanging test.

extensions/mattermost/src/mattermost/monitor-websocket.test.ts

@@ -185,6 +185,8 @@ describe("mattermost websocket monitor", () => {
       webSocketFactory: () => socket,
     });
 
+    const connected = connectOnce();
+    queueMicrotask(() => {
       socket.emitOpen();
       socket.emitMessage(
         Buffer.from(
@@ -201,8 +203,9 @@ describe("mattermost websocket monitor", () => {
         ),
       );
       socket.emitClose(1000);
+    });
 
-    await connectOnce();
+    await connected;
 
     expect(onReaction).toHaveBeenCalledTimes(1);
     expect(onPosted).not.toHaveBeenCalled();