Docs: Fix function types. (#30559)

src/materials/nodes/NodeMaterial.js

@@ -292,7 +292,7 @@ class NodeMaterial extends Material {
 		 * 	return shadow.mix( color( 0xff0000 ), 1 ); // modify shadow color
 		 * } );
 		 *
-		 * @type {?(Function<vec4>|FunctionNode<vec4>)}
+		 * @type {?(Function|FunctionNode<vec4>)}
 		 * @default null
 		 */
 		this.receivedShadowNode = null;

src/materials/nodes/VolumeNodeMaterial.js

@@ -44,7 +44,7 @@ class VolumeNodeMaterial extends NodeMaterial {
 		/**
 		 * Node used for scattering calculations.
 		 *
-		 * @type {Function<vec4>|FunctionNode<vec4>}
+		 * @type {Function|FunctionNode<vec4>}
 		 * @default null
 		 */
 		this.scatteringNode = null;