ci: upgrade wayland to 1.20.0
This will be useful to use features introduced in wayland 1.20, e.g. event destructors (see !36 (merged)).
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
This will be useful to use features introduced in wayland 1.20, e.g. event destructors (see !36 (merged)).