server: request xdg-shell v2

Wlroots does not yet support the newer xdg-shell versions and now
requires the compositor to set the supported xdg-shell version during
creation. Set this to v2 for sway as well.

Fixes https://github.com/swaywm/sway/issues/7001

sway/server.c

@@ -72,6 +72,8 @@ static void handle_drm_lease_request(struct wl_listener *listener, void *data) {
 	}
 }
 
+#define SWAY_XDG_SHELL_VERSION	2
+
 bool server_init(struct sway_server *server) {
 	sway_log(SWAY_DEBUG, "Initializing Wayland server");
 
@@ -126,7 +128,8 @@ bool server_init(struct sway_server *server) {
 		&server->layer_shell_surface);
 	server->layer_shell_surface.notify = handle_layer_shell_surface;
 
-	server->xdg_shell = wlr_xdg_shell_create(server->wl_display);
+	server->xdg_shell = wlr_xdg_shell_create(server->wl_display,
+		SWAY_XDG_SHELL_VERSION);
 	wl_signal_add(&server->xdg_shell->events.new_surface,
 		&server->xdg_shell_surface);
 	server->xdg_shell_surface.notify = handle_xdg_shell_surface;