Fix dangling promises.

packages/apputils/src/dialog.ts

@@ -99,7 +99,7 @@ export class Dialog<T> extends Widget {
     this._focusNodeSelector = options.focusNodeSelector;
 
     // Add new dialogs to the tracker.
-    Dialog.tracker.add(this);
+    void Dialog.tracker.add(this);
   }
 
   /**

tests/test-apputils/src/clientsession.spec.ts

@@ -202,7 +202,7 @@ describe('@jupyterlab/apputils', () => {
 
       it('should connect to an existing kernel', async () => {
         // Shut down and dispose the session so it can be re-instantiated.
-        session.shutdown();
+        await session.shutdown();
         session.dispose();
 
         const other = await manager.startNew({ path: UUID.uuid4() });