Update MaterialLoader.js (#24402)

Adding the field glslVersion

src/loaders/MaterialLoader.js

@@ -225,6 +225,7 @@ class MaterialLoader extends Loader {
 		if ( json.defines !== undefined ) material.defines = json.defines;
 		if ( json.vertexShader !== undefined ) material.vertexShader = json.vertexShader;
 		if ( json.fragmentShader !== undefined ) material.fragmentShader = json.fragmentShader;
+		if ( json.glslVersion !== undefined ) material.glslVersion = json.glslVersion;
 
 		if ( json.extensions !== undefined ) {