x11-toolkits/gtk4-layer-shell: add new port
A library for using the Layer Shell Wayland protocol with GTK4. With
this library you can build desktop shell components such as panels,
notifications and wallpapers. You can use it to anchor your windows to
a corner or edge of the output, or stretch them across the entire
output. This Library is compatible with C, C++ and any language that
supports GObject introspection files (Python, Vala, etc).