Fix `@since` in new files docblocks

src/TestSuite/EmailAssertTrait.php

@@ -9,7 +9,7 @@
  *
  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  * @link          http://cakephp.org CakePHP(tm) Project
- * @since         3.3.1
+ * @since         3.3.3
  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
  */
 namespace Cake\TestSuite;

tests/TestCase/TestSuite/EmailAssertTraitTest.php

@@ -9,7 +9,7 @@
  *
  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  * @link          http://cakephp.org CakePHP(tm) Project
- * @since         3.3.1
+ * @since         3.3.3
  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
  */
 namespace Cake\Test\TestCase\TestSuite;

tests/test_app/TestApp/Mailer/TestUserMailer.php

@@ -9,7 +9,7 @@
  *
  * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
  * @link          http://book.cakephp.org/2.0/en/development/testing.html CakePHP(tm) Tests
- * @since         3.4.0
+ * @since         3.3.3
  * @license       http://www.opensource.org/licenses/mit-license.php MIT License
  */
 namespace TestApp\Mailer;