Automated Project Update Bot fixes

Relates to #3434000. This merge request was automatically created by the Project Update Bot. It contains the changes from run 11-477325.

tests/src/Functional/LoadTest.php

@@ -14,6 +14,11 @@ use Drupal\Tests\BrowserTestBase;
  */
 class LoadTest extends BrowserTestBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
   /**
    * Modules to enable.
    *