WebGPURenderer: Fix shadows on objects with receiveShadow=false

[RenaudRohlinger]

Description
Currently the meshes will always receive shadows if their castShadow property is true regardless if receiveShadow is false. This PR fixes the issue by resetting the colorNode in AnalyticLightNode when the shadow map is not needed.

For example, here the box is defined with the following properties:

box.castShadow = true;
box.receiveShadow = false;

Before:

After:

This contribution is funded by Utsubo

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
683.5 kB (169.2 kB)	683.5 kB (169.2 kB)	+0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
460.7 kB (111.1 kB)	460.7 kB (111.1 kB)	+0 B