westoy: Remove some accessors for wl_shell / wl_shell_surface

We want to remove support for these deprecated interfaces. Since
nothing is using them, this is a simple change.

clients/window.c

@@ -1940,12 +1940,6 @@ window_get_wl_surface(struct window *window)
 	return window->main_surface->surface;
 }
 
-struct wl_shell_surface *
-window_get_wl_shell_surface(struct window *window)
-{
-	return window->shell_surface;
-}
-
 static void
 tooltip_redraw_handler(struct widget *widget, void *data)
 {
@@ -5254,12 +5248,6 @@ display_get_argb_egl_config(struct display *d)
 	return d->argb_config;
 }
 
-struct wl_shell *
-display_get_shell(struct display *display)
-{
-	return display->shell;
-}
-
 int
 display_acquire_window_surface(struct display *display,
 			       struct window *window,

clients/window.h

@@ -87,9 +87,6 @@ display_get_cairo_device(struct display *display);
 struct wl_compositor *
 display_get_compositor(struct display *display);
 
-struct wl_shell *
-display_get_shell(struct display *display);
-
 struct output *
 display_get_output(struct display *display);
 
@@ -349,9 +346,6 @@ window_get_surface(struct window *window);
 struct wl_surface *
 window_get_wl_surface(struct window *window);
 
-struct wl_shell_surface *
-window_get_wl_shell_surface(struct window *window);
-
 enum window_buffer_type {
 	WINDOW_BUFFER_TYPE_EGL_WINDOW,
 	WINDOW_BUFFER_TYPE_SHM,