Use jetpack autoloader and composer instead of namespace rewrite

inc/helpers/validation-rules/class-site-template.php

@@ -9,7 +9,7 @@
 
 namespace WP_Ultimo\Helpers\Validation_Rules;
 
-use \WP_Ultimo\Dependencies\Rakit\Validation\Rule;
+use \Rakit\Validation\Rule;
 use \WP_Ultimo\Checkout\Checkout;
 use \WP_Ultimo\Database\Sites\Site_Type;