wayland: don't send set_buffer_scale on wl_surface below version 3

wl_surface::set_buffer_scale is available since version 3. Sending it
on an older surface is a protocol error that terminates the connection.
This could happen when setting a custom cursor on a compositor without
wp_viewporter. The neighboring damage call already checks the version.

winit-wayland/src/window/state.rs

@@ -814,10 +814,12 @@ impl WindowState {
                 let size = PhysicalSize::new(cursor.w, cursor.h).to_logical(scale);
                 viewport.set_destination(size.width, size.height);
                 scale
-            } else {
+            } else if surface.version() >= 3 {
                 let scale = surface.data::<SurfaceData>().unwrap().surface_data().scale_factor();
                 surface.set_buffer_scale(scale);
                 scale as f64
+            } else {
+                1.
             };
 
             surface.attach(Some(cursor.buffer.wl_buffer()), 0, 0);