Remove useless schedule (for now)

src/core/app/app.rs

@@ -1,6 +1,6 @@
 use std::error::Error;
 
-use bevy_ecs::{schedule::Schedules, world::World};
+use bevy_ecs::world::World;
 
 pub enum AppExit {
     Success,
@@ -24,11 +24,8 @@ pub struct App {
 
 impl Default for App {
     fn default() -> Self {
-        let mut world = World::new();
-        world.init_resource::<Schedules>();
-
         Self {
-            world,
+            world: World::new(),
             runner: None,
         }
     }