Change many metal nodes to use default metal sounds

mods/xpanes/init.lua

@@ -164,7 +164,7 @@ xpanes.register_pane("bar", {
 	inventory_image = "xpanes_bar.png",
 	wield_image = "xpanes_bar.png",
 	groups = {cracky=2},
-	sounds = default.node_sound_stone_defaults(),
+	sounds = default.node_sound_metal_defaults(),
 	recipe = {
 		{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"},
 		{"default:steel_ingot", "default:steel_ingot", "default:steel_ingot"}