The `videosink` refernce in main() is a floating one, so it should not be unref'ed (the playbin practically takes ownership of it). This prevents a "gst_object_unref: assertion '((GObject *) object)->ref_count > 0' failed" at runtime. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6883>