Bump from 1.45 to current upstream stable.
1.48 introduces the new 'enum-header' wayland-scanner mode that
generates a *-enum.h header per protocol. wlroots 0.20+ relies
on these. Extend Build/InstallDev to copy
/usr/include/wayland-protocols/*.h into staging so consumers can
include them via <wayland-protocols/...-enum.h>.
Link: https://gitlab.freedesktop.org/wayland/wayland-protocols/-/releases/1.48
Signed-off-by: Daniel Golle <daniel@makrotopia.org>