docs: fix tricky sample code

Author: kenjis

user_guide_src/source/database/utilities/001.php

@@ -4,7 +4,7 @@
     protected $table      = 'foo';
     protected $primaryKey = 'id';
 };
-$db = \Closure::bind(static fn ($model) => $model->db, null, $model)($model);
 
-$util = (new \CodeIgniter\Database\Database())->loadUtils($db);
+$util = \CodeIgniter\Database\Config::utils();
+
 echo $util->getXMLFromResult($model->get());