fix deprecation from Extension class

[IndraGunawan]

The "Symfony\Component\HttpKernel\DependencyInjection\Extension" class is considered internal since Symfony 7.1, to be
deprecated in 8.1; use Symfony\Component\DependencyInjection\Extension\Extension instead. It may change without further
notice. You should not use it from
"PixelOpen\CloudflareTurnstileBundle\DependencyInjection\PixelOpenCloudflareTurnstileExtension".