remove dead comment.

js/player.mjs

@@ -12,7 +12,6 @@ function out_of_bounds (x, y) {
 		y < 0 || y >= world.BOX_SIZE
 }
 
-// TODO: clean up this by making tile movement be performed by the world code.
 export function set_player_pos (x, y) {
 	const previous_x = player.x;
 	const previous_y = player.y;