Fix clippy::let_and_return in bevy_ecs (#18481)

# Objective

- `clippy::let_and_return` fails in `bevy_ecs`

## Solution

- Fixed it!

## Testing

- CI

crates/bevy_ecs/src/archetype.rs

@@ -942,7 +942,7 @@ impl Archetypes {
         let archetypes = &mut self.archetypes;
         let archetype_component_count = &mut self.archetype_component_count;
         let component_index = &mut self.by_component;
-        let archetype_id = *self
+        *self
             .by_components
             .entry(archetype_identity)
             .or_insert_with_key(move |identity| {
@@ -975,8 +975,7 @@ impl Archetypes {
                         .zip(sparse_set_archetype_components),
                 ));
                 id
-            });
-        archetype_id
+            })
     }
 
     /// Returns the number of components that are stored in archetypes.

crates/bevy_ecs/src/bundle.rs

@@ -1585,7 +1585,7 @@ impl Bundles {
         storages: &mut Storages,
     ) -> BundleId {
         let bundle_infos = &mut self.bundle_infos;
-        let id = *self.bundle_ids.entry(TypeId::of::<T>()).or_insert_with(|| {
+        *self.bundle_ids.entry(TypeId::of::<T>()).or_insert_with(|| {
             let mut component_ids= Vec::new();
             T::component_ids(components, &mut |id| component_ids.push(id));
             let id = BundleId(bundle_infos.len());
@@ -1597,8 +1597,7 @@ impl Bundles {
                 unsafe { BundleInfo::new(core::any::type_name::<T>(), storages, components, component_ids, id) };
             bundle_infos.push(bundle_info);
             id
-        });
-        id
+        })
     }
 
     /// Registers a new [`BundleInfo`], which contains both explicit and required components for a statically known type.