These are not used yet but will likely be useful in the future. Rust 1.79 (nightly) is warning about them being unused. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6601>
This drops invalid, unknown or uninteresting PTP messages in the helper process already instead of forwarding them to the main process. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4665>