Naga export (#3714)

# Objective

In order to create a glsl shader, we must provide the `naga::ShaderStage` type which is not exported by bevy, meaning a user would have to manually include naga just to access this type.

`pub fn from_glsl(source: impl Into<Cow<'static, str>>, stage: naga::ShaderStage) -> Shader {`

## Solution

Re-rexport naga::ShaderStage from `render_resources`

crates/bevy_render/src/render_resource/mod.rs

@@ -42,3 +42,5 @@ pub use wgpu::{
 };
 
 pub use bevy_crevice::*;
+
+pub use naga::ShaderStage;