error in php 8 + 8.1 - php 7.4 works fine

[asche76]

got this error in php 8.0.26 and 8.1x

(1/1) #1476107295 TYPO3\CMS\Core\Error\Exception
PHP Warning: Undefined variable $function in /var/customers/webs/web23/typo3conf/ext/newsslider/Classes/ViewHelpers/InlineJsViewHelper.php line 283

in /var/customers/webs/web23/typo3/sysext/core/Classes/Error/ErrorHandler.php line 137

ext works fine in php 7.4