tree/output: Rely on modeset arranging root

output_enable/output_disable are only called from modeset, and from
output destroy which requests modeset. As such, they can rely on the
modeset handling arrange.

sway/tree/output.c

@@ -183,9 +183,6 @@ void output_enable(struct sway_output *output) {
 	input_manager_configure_xcursor();
 
 	wl_signal_emit_mutable(&root->events.new_node, &output->node);
-
-	arrange_layers(output);
-	arrange_root();
 }
 
 static void evacuate_sticky(struct sway_workspace *old_ws,
@@ -300,13 +297,6 @@ void output_disable(struct sway_output *output) {
 	list_del(root->outputs, index);
 
 	output->enabled = false;
-
-	arrange_root();
-
-	// Reconfigure all devices, since devices with map_to_output directives for
-	// an output that goes offline should stop sending events as long as the
-	// output remains offline.
-	input_manager_configure_all_input_mappings();
 }
 
 void output_begin_destroy(struct sway_output *output) {