By using wl_output_release(), GDK lets the compositor to clean up the
output global more nicely.
For example, currently, most compositors remove the global and then
destroy it later after N seconds expire. With this, the compositor could
experiment with destroying the output global once all its resources are
destroyed.
The xdg_output v2 interface has a `name` property that reflects the
output name coming from the compositor.
This is the closest thing we can get to a connector name.
Remove all the old 2.x and 3.x version annotations.
GTK+ 4 is a new start, and from the perspective of a
GTK+ 4 developer all these APIs have been around since
the beginning.
