Fix clippy lints.

Author: Anders429

src/system/schedule/claim/get/registry.rs

@@ -1,5 +1,3 @@
-use crate::registry;
-
 pub struct Index;
 
 pub trait Get<T, I> {

src/system/schedule/scheduler.rs

@@ -62,7 +62,7 @@ where
     (T, U): Stager<'a, R, claim::Null, I, P, RI, SFI, SVI, SP, SI, SQ>,
     <(T, U) as Stager<'a, R, claim::Null, I, P, RI, SFI, SVI, SP, SI, SQ>>::Remainder:
         Scheduler<'a, R, IS, PS, RIS, SFIS, SVIS, SPS, SIS, SQS>,
-    R: 'a,
+    R: Registry + 'a,
     I: 'a,
     P: 'a,
     RI: 'a,
@@ -71,7 +71,6 @@ where
     SP: 'a,
     SI: 'a,
     SQ: 'a,
-    R: Registry,
 {
     type Stages = (
         <(T, U) as Stager<'a, R, claim::Null, I, P, RI, SFI, SVI, SP, SI, SQ>>::Stage,

src/system/schedule/stage.rs

@@ -20,7 +20,7 @@ impl<R> Stage<'_, R, Null, Null, Null, Null, Null> for Null
 where
     R: Registry,
 {
-    fn run(&mut self, world: SendableWorld<R>) {}
+    fn run(&mut self, _world: SendableWorld<R>) {}
 }
 
 impl<'a, R, T, U, FI, FIS, VI, VIS, P, PS, I, IS, Q, QS>