AC-681: Create phpcs static check for PhtmlTemplateTest

Author: eliseacornejo

Magento2/Sniffs/Legacy/PhtmlTemplateSniff.php

@@ -1,4 +1,9 @@
 <?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types = 1);
 
 namespace Magento2\Sniffs\Legacy;