scene example: remove unnecessary reflect(FromWorld) (#11938)

# Objective

- `#[reflect(FromWorld)]` was added to `ComponentB` somewhere between
`v0.12.1` and `v0.13.0`, but it is unnecessary

## Solution

- remove the unnecessary `FromWorld`

examples/scene/scene.rs

@@ -34,7 +34,7 @@ struct ComponentA {
 // trait comes into play. `FromWorld` gives you access to your App's current ECS `Resources`
 // when you construct your component.
 #[derive(Component, Reflect)]
-#[reflect(Component, FromWorld)]
+#[reflect(Component)]
 struct ComponentB {
     pub value: String,
     #[reflect(skip_serializing)]