[Joomla 4.0] Warnings when CiviCRM is uninstalled

Two PHP warnings are displayed when uninstalling CiviCRM from Joomla 4.0 alpha 11:

 Warning: require_once(CRM/Utils/String.php): failed to open stream: No such file or directory in /var/www/html/j4/administrator/components/com_civicrm/script.civicrm.php on line 226

Fatal error: require_once(): Failed opening required 'CRM/Utils/String.php' (include_path='.:/usr/share/pear:/usr/share/php') in /var/www/html/j4/administrator/components/com_civicrm/script.civicrm.php on line 226