test: use `await` to call "closeWindow" (#38172)

spec/api-web-contents-view-spec.ts

@@ -4,7 +4,11 @@ import { BaseWindow, WebContentsView } from 'electron/main';
 
 describe('WebContentsView', () => {
   let w: BaseWindow;
-  afterEach(() => closeWindow(w as any).then(() => { w = null as unknown as BaseWindow; }));
+
+  afterEach(async () => {
+    await closeWindow(w as any);
+    w = null as unknown as BaseWindow;
+  });
 
   it('can be used as content view', () => {
     w = new BaseWindow({ show: false });

spec/extensions-spec.ts

@@ -562,9 +562,10 @@ describe('chrome extensions', () => {
             });
           });
 
-          afterEach(() => {
+          afterEach(async () => {
             removeAllExtensions();
-            return closeWindow(w).then(() => { w = null as unknown as BrowserWindow; });
+            await closeWindow(w);
+            w = null as unknown as BrowserWindow;
           });
 
           it('should run content script at document_start', async () => {