fix: collapse animation not work, close #4856

components/_util/requestAnimationTimeout.js

@@ -5,7 +5,7 @@ const raf = getRequestAnimationFrame();
 
 export const cancelAnimationTimeout = frame => caf(frame.id);
 
-export const requestAnimationTimeout = (callback, delay) => {
+export const requestAnimationTimeout = (callback, delay = 0) => {
   const start = Date.now();
   function timeout() {
     if (Date.now() - start >= delay) {

components/collapse/CollapsePanel.tsx

@@ -79,7 +79,7 @@ export default defineComponent({
         ></PanelContent>
       );
       const transitionProps = {
-        appear: true,
+        appear: false,
         css: false,
         ...openAnimation,
       };