Issue #3233010 by alexpott, longwave:...

Issue #3233010 by alexpott, longwave: drupal_phpunit_contrib_extension_directory_roots() passes NULL to file_exists() causing deprecations in PHP 8.1

core/tests/bootstrap.php

@@ -67,7 +67,7 @@ function drupal_phpunit_contrib_extension_directory_roots($root = NULL) {
     $paths[] = is_dir("$path/profiles") ? realpath("$path/profiles") : NULL;
     $paths[] = is_dir("$path/themes") ? realpath("$path/themes") : NULL;
   }
-  return array_filter($paths, 'file_exists');
+  return array_filter($paths);
 }
 
 /**