Examples: Improve shadow map size in `webgpu_tsl_angular_slicing` (#29499)

examples/webgpu_tsl_angular_slicing.html

@@ -65,7 +65,7 @@
 				const directionalLight = new THREE.DirectionalLight( '#ffffff', 4 );
 				directionalLight.position.set( 6.25, 3, 4 );
 				directionalLight.castShadow = true;
-				directionalLight.shadow.mapSize.set( 1024, 1024 );
+				directionalLight.shadow.mapSize.set( 2048, 2048 );
 				directionalLight.shadow.camera.near = 0.1;
 				directionalLight.shadow.camera.far = 30;
 				directionalLight.shadow.camera.top = 8;