Issue #3050172 by naveenvalecha, claudiu.cristea: Move MigrateLanguageTest...

Issue #3050172 by naveenvalecha, claudiu.cristea: Move MigrateLanguageTest under Kernel tests namespace

core/modules/language/tests/src/Functional/Migrate/MigrateLanguageTest.php → core/modules/language/tests/src/Kernel/Migrate/d6/MigrateLanguageTest.php

 <?php
 
-namespace Drupal\Tests\language\Functional\Migrate;
+namespace Drupal\Tests\language\Kernel\Migrate\d6;
 
 use Drupal\language\ConfigurableLanguageInterface;
 use Drupal\language\Entity\ConfigurableLanguage;