Upgrade sabberworm/php-css-parser to the latest version

While bumping the PHP version in the composer.json file, an issue with sabberworm/php-css-parser library version hight than 8.2 has been found. It seems the latest versions have a but with comments which are causing some PHPUnit failures.
This issue is to fix this bug in order to be able to upgrade sabberworm/php-css-parser to the latest.