free coin in 3D platformer

(cherry picked from commit 76bfb10deb)

3d/platformer/coin.gd

@@ -9,3 +9,9 @@ func _on_coin_body_enter(body):
 	if (not taken and body extends preload("res://player.gd")):
 		get_node("anim").play("take")
 		taken = true
+
+
+func _on_anim_finished():
+	if get_node("anim").get_current_animation() == "take":
+		queue_free()
+