x11-display: Use X11 UI scaling factor for cursor theme size

As with Xsettings, we want to use the X11 UI scaling factor to set the
cursor size, so that clients use a larger theme, both when using
`native-xwayland-scaling` and a physical layout mode.

Fixes: 6e8c7c5f84 ("Add experimental mode to use native scaling of Xwayland clients")
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3992>

src/wayland/meta-wayland-cursor-surface.c

@@ -103,8 +103,19 @@ cursor_sprite_prepare_at (MetaCursorSprite         *cursor_sprite,
     meta_monitor_manager_get_logical_monitor_at (monitor_manager, x, y);
   if (logical_monitor)
     {
-      int surface_scale = surface->applied_state.scale;
+      int surface_scale;
       float texture_scale;
+#ifdef HAVE_XWAYLAND
+      MetaWaylandCompositor *wayland_compositor =
+        meta_context_get_wayland_compositor (context);
+      MetaXWaylandManager *xwayland_manager =
+        &wayland_compositor->xwayland_manager;
+
+      if (meta_wayland_surface_is_xwayland (surface))
+        surface_scale = meta_xwayland_get_x11_ui_scaling_factor (xwayland_manager);
+      else
+#endif /* HAVE_XWAYLAND */
+        surface_scale = surface->applied_state.scale;
 
       if (meta_backend_is_stage_views_scaled (backend))
         texture_scale = 1.0f / surface_scale;

src/x11/meta-x11-display.c

@@ -1965,7 +1965,7 @@ update_cursor_theme (MetaX11Display *x11_display)
         MetaXWaylandManager *xwayland_manager =
           &wayland_compositor->xwayland_manager;
 
-        scale = meta_xwayland_get_effective_scale (xwayland_manager);
+        scale = meta_xwayland_get_x11_ui_scaling_factor (xwayland_manager);
 #endif
         break;
       }