bevy_state: Make reflect module public (#14667)

# Objective

CI is
[failing](https://github.com/bevyengine/bevy/actions/runs/10308658332/job/28536587448)
due to certain methods not being used.

## Solution

Make the `reflect` module public so that these warnings go away and so
that the `pub` items in these modules can be used.

## Testing

CI should pass.

crates/bevy_state/src/lib.rs

@@ -41,7 +41,7 @@ pub mod state_scoped;
 
 #[cfg(feature = "bevy_reflect")]
 /// Provides definitions for the basic traits required by the state system
-mod reflect;
+pub mod reflect;
 
 /// Most commonly used re-exported types.
 pub mod prelude {