* Expose an actual constructor from caps * Error out in overrides for code that was using the "manual allocation" pattern which only worked by chance. Direct the script writer to the new_from_caps constructor instead. Fixes https://gitlab.freedesktop.org/gstreamer/gst-python/-/issues/47 Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1571>