desktop/transaction: Deactivate workspace on inactive outputs

If the output is not active, it might not have a valid geometry to
arrange for. Outputs do not gain a geometry until modeset, so if an
output is connected with a configuration present to disable it, it will
not have a geometry. If the output has a past workspace restored, this
will be attemtped arranged to fit a 0x0 rectangle, which asserts when
trying to sort out borders.

Consider the workspace activated only if the output itself is active to
get the scene nodes disabled.

sway/desktop/transaction.c

@@ -559,7 +559,7 @@ static void arrange_output(struct sway_output *output, int width, int height) {
 	for (int i = 0; i < output->current.workspaces->length; i++) {
 		struct sway_workspace *child = output->current.workspaces->items[i];
 
-		bool activated = output->current.active_workspace == child;
+		bool activated = output->current.active_workspace == child && output->wlr_output->enabled;
 
 		wlr_scene_node_reparent(&child->layers.tiling->node, output->layers.tiling);
 		wlr_scene_node_reparent(&child->layers.fullscreen->node, output->layers.fullscreen);