Revert "#37796: Fixed namespace for integration class"

This reverts commit de4dd4e.

Author: Indraniks

dev/tests/integration/testsuite/Magento/Directory/Setup/DataInstallerTest.php

@@ -1,6 +1,6 @@
 <?php
 
-namespace Magento\Directory\Setup;
+namespace integration\testsuite\Magento\Directory\Setup;
 
 use PHPUnit\Framework\TestCase;
 use Magento\TestFramework\Helper\Bootstrap;