fix by cargo

src/music.rs

@@ -3,12 +3,11 @@ use crate::{polygon_draw::*, utils::string_to_color};
 use serde::{Deserialize, Serialize};
 
 use kira::{
-    AudioManager, AudioManagerSettings, DefaultBackend, sound::static_sound::StaticSoundData,
+    AudioManager, sound::static_sound::StaticSoundData,
 };
 
 use std::f32::consts::PI;
 use std::time::Duration;
-use std::time::Instant;
 
 #[derive(Serialize, Deserialize)]
 pub struct Music {