fix 16-bit limit (#22440)

examples/webgpu_compute.html

@@ -55,7 +55,7 @@
 				scene = new THREE.Scene();
 				scene.background = new THREE.Color( 0x000000 );
 
-				const particleNum = 100000;
+				const particleNum = 50000; // 16-bit limit
 				const particleSize = 3;
 
 				const particleArray = new Float32Array( particleNum * particleSize );