FILTER_SANITIZE_STRING warning

Hi there,

This plugin uses the deprecated ( as of PHP 8.1.0 ) FILTER_SANITIZE_STRING in ml-slider\admin\Table.php line 137.

    protected function process_action()
    {
        if (isset($_POST['_wpnonce']) && ! empty($_POST['_wpnonce'])) {
            $nonce  = filter_input( INPUT_POST, '_wpnonce', FILTER_SANITIZE_STRING );
            $action = 'bulk-' . $this->_args['plural'];
            if ( ! wp_verify_nonce($nonce, $action)) {
                wp_die( 'Nope! Security check failed!' );
            }
        }

According to PHP.net it should be replaced with htmlspecialchars() – https://www.php.net/manual/en/function.htmlspecialchars.php

Looking forward to an update on this issue.

Thank you!