Fix point light radius (#9493)

# Objective

Fixes #9488

## Solution

Set point light radius to always be 0.0. Reading this value from glTF
would require using application specific extras property.

---

## Changelog

### Fixed

- #9488 Point Lights use Range for Radius when importing from GLTF

crates/bevy_gltf/src/loader.rs

@@ -858,7 +858,7 @@ fn load_node(
  // For a point light, luminous power = 4 * pi * luminous intensity
  intensity: light.intensity() * std::f32::consts::PI * 4.0,
  range: light.range().unwrap_or(20.0),
- radius: light.range().unwrap_or(0.0),
+ radius: 0.0,
  ..Default::default()
  },
  ..Default::default()