WebGLRenderer: add vertexNormals to WebGLProgramParameters for normal bias fallback (#33391)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: Methuselah96

types/three/src/renderers/webgl/WebGLPrograms.d.ts

@@ -131,6 +131,7 @@ export interface WebGLProgramParameters {
     //
 
     vertexTangents: boolean;
+    vertexNormals: boolean;
     vertexColors: boolean;
     vertexAlphas: boolean;
     vertexUv1s: boolean;