Smarty syntax error: invalid attribute name: '$groups'

Installed on CiviCRM 5.67.0 with WordPress 6.5.4 (PHP 8.1.29) and added to settings file:

define('GROUPGROWTH_GROUP_IDS', '8,10,39,41,43,45,47,49,51,53,55');

Now I have this error after visiting https://[domain]de/wp-admin/admin.php?page=CiviCRM&q=civicrm%2Fgroupgrowth

Fatal error: Smarty error: [in CRM/Groupgrowth/Page/Chart.tpl line 4]: syntax error: invalid attribute name: '$groups' (Smarty_Compiler.class.php, line 1549) in /var/www/vhosts/meine.dvpw.de/httpdocs/wp-content/plugins/civicrm/civicrm/packages/Smarty/Smarty.class.php on line 1100

Who can help me? I think I still have Smarty v2 installed.