chore: feature check

Author: itsdouges

packages/fiber/src/core/utils.tsx

@@ -31,14 +31,12 @@ export type Act = <T = any>(cb: () => Promise<T>) => Promise<T>
 /**
  * Safely flush async effects when testing, simulating a legacy root.
  */
-export const act: Act = async (cb) => {
-  const React = await import('react')
-
+export const act: Act = (cb) => {
   if ('act' in React) {
     return React.act(cb)
   }
 
-  throw new Error('R3F: React.act is unavailable in this environment.')
+  throw new Error('act(...) is not supported in production builds of React')
 }
 
 export type Camera = (THREE.OrthographicCamera | THREE.PerspectiveCamera) & { manual?: boolean }