Use the explicit valid clocktime handler instead Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8286>
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7455>
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2992>