make raf a noop on server (#3324)

src/runtime/internal/environment.ts

@@ -1,10 +1,12 @@
+import { noop } from './utils';
+
 export const is_client = typeof window !== 'undefined';
 
 export let now: () => number = is_client
 	? () => window.performance.now()
 	: () => Date.now();
 
-export let raf = cb => requestAnimationFrame(cb);
+export let raf = is_client ? cb => requestAnimationFrame(cb) : noop;
 
 // used internally for testing
 export function set_now(fn) {