test(many): migrate to new toHaveScreenshot API (#26797)

core/src/components/alert/test/basic/alert.e2e.ts

@@ -18,7 +18,7 @@ const testAlert = async (page: E2EPage, buttonID: string) => {
   const alert = await openAlert(page, buttonID);
 
   await expect(alert).toBeVisible();
-  expect(await alert.screenshot()).toMatchSnapshot(`alert-${buttonID}-${page.getSnapshotSettings()}.png`);
+  await expect(alert).toHaveScreenshot(`alert-${buttonID}-${page.getSnapshotSettings()}.png`);
 
   await alert.evaluate((el: HTMLIonAlertElement) => el.dismiss());
   await didDismiss.next();

core/src/components/alert/test/standalone/alert.e2e.ts

@@ -11,6 +11,6 @@ test.describe('alert: standalone', () => {
     await page.click('#basic');
     await didPresent.next();
 
-    expect(await alert.screenshot()).toMatchSnapshot(`alert-standalone-${page.getSnapshotSettings()}.png`);
+    await expect(alert).toHaveScreenshot(`alert-standalone-${page.getSnapshotSettings()}.png`);
   });
 });