Optimize use statement (#5992)

Just a very small `use` statement thing. Check the changed file.

crates/bevy_ecs/src/event.rs

@@ -4,11 +4,7 @@ use crate as bevy_ecs;
 use crate::system::{Local, Res, ResMut, Resource, SystemParam};
 use bevy_utils::tracing::{trace, warn};
 use std::ops::{Deref, DerefMut};
-use std::{
-    fmt::{self},
-    hash::Hash,
-    marker::PhantomData,
-};
+use std::{fmt, hash::Hash, marker::PhantomData};
 
 /// A type that can be stored in an [`Events<E>`] resource
 /// You can conveniently access events using the [`EventReader`] and [`EventWriter`] system parameter.