Examples: Fix shadow map enabled in `webgpu_instancing_morph` (#29553)

examples/webgpu_instancing_morph.html

@@ -140,6 +140,7 @@
 				renderer.setAnimationLoop( animate );
 				renderer.setPixelRatio( window.devicePixelRatio );
 				renderer.setSize( window.innerWidth, window.innerHeight );
+				renderer.shadowMap.enabled = true;
 				document.body.appendChild( renderer.domElement );
 
 				window.addEventListener( 'resize', onWindowResize );