[12.x] Add missing assertSentTimes method

mail.md

@@ -1291,6 +1291,9 @@ test('orders can be shipped', function () {
     // Assert a mailable was not sent...
     Mail::assertNotSent(AnotherMailable::class);
 
+    // Assert a mailable was sent twice...
+    Mail::assertSentTimes(OrderShipped::class, 2);
+
     // Assert 3 total mailables were sent...
     Mail::assertSentCount(3);
 });
@@ -1331,6 +1334,9 @@ class ExampleTest extends TestCase
         // Assert a mailable was not sent...
         Mail::assertNotSent(AnotherMailable::class);
 
+        // Assert a mailable was sent twice...
+        Mail::assertSentTimes(OrderShipped::class, 2);
+
         // Assert 3 total mailables were sent...
         Mail::assertSentCount(3);
     }

notifications.md

@@ -1668,6 +1668,9 @@ test('orders can be shipped', function () {
         [$user], AnotherNotification::class
     );
 
+    // Assert a notification was sent twice...
+    Notification::assertSentTimes(WeeklyReminder::class, 2);
+
     // Assert that a given number of notifications were sent...
     Notification::assertCount(3);
 });