MAGETWO-93994: Switch default search engine from MySQL to ElasticSearch

- Add strict type declaration

Author: tjwiebell

app/code/Magento/CatalogSearch/Setup/Patch/Data/MySQLSearchDeprecationNotification.php

@@ -3,6 +3,8 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\CatalogSearch\Setup\Patch\Data;
 
 class MySQLSearchDeprecationNotification implements \Magento\Framework\Setup\Patch\DataPatchInterface