refactor: removed getRegistrationControl() from Authenticator (was unused)

src/QUI/Auth/Google2Fa/Auth.php

@@ -186,14 +186,6 @@ public static function getLoginControl()
         return new QUI\Auth\Google2Fa\Controls\Login();
     }
 
-    /**
-     * @return \QUI\Control
-     */
-    public static function getRegisterControl()
-    {
-        return null;
-    }
-
     /**
      * @return \QUI\Control
      */