Subprojects that use meson.override_dependency() do not require the
caller to provide the dependency variable name inside the subproject.
We also don't want to provide the *subproject* name, because the
subproject name can be `pango-1.50.12` instead of `pango` when using
wrap-file to download the tarball instead of using wrap-git. This
causes the pango subproject to be executed twice when using gtk as
a subproject inside gstreamer (which uses pango-1.50.12 as
a wrap-file).
All the dependencies we use can be switched in this way, but the
remaining ones need to be changed to use meson.override_dependency()
first.
This makes the hotspot of DND surfaces work when using the Vulkan and
OpenGL renderers.
This bumps the CI image used to the newly built image. This is needed to
install a new enough libwayland-client.so needed for wl_surface.offset.
This is done by adding wayland as a meson subproject, building it
on-demand if the version in the system is not new enough. As
libwayland-client.so is pulled in implicitly when linking to gtk4, the
compile step needs LD_LIBRARY_PATH set to make ld find the right library
to link to.
