Bevy 0.16 upgrade (#24)

src/abilities/mod.rs

@@ -88,16 +88,12 @@ fn on_trigger_state(
     mut commands: Commands,
     player_rot: Query<&Transform, With<PlayerBodyMesh>>,
     player_query: Query<(Entity, &AimTarget), With<Player>>,
-    mut active_heads: Query<&mut ActiveHeads, With<Player>>,
+    mut active_heads: Single<&mut ActiveHeads, With<Player>>,
     heads_db: Res<HeadsDatabase>,
     time: Res<Time>,
     character: CharacterHierarchy,
 ) {
     if matches!(trigger.event(), TriggerState::Active) {
-        let Ok(mut active_heads) = active_heads.get_single_mut() else {
-            return;
-        };
-
         let Some(state) = active_heads.current() else {
             return;
         };