refactor: modify the parameter type of `access` function (#9596)

src/access.ts

@@ -1,8 +1,8 @@
 /**
  * @see https://umijs.org/zh-CN/plugins/plugin-access
  * */
-export default function access(initialState: { currentUser?: API.CurrentUser | undefined }) {
+export default function access(initialState: { currentUser?: API.CurrentUser } | undefined) {
-  const { currentUser } = initialState || {};
+  const { currentUser } = initialState ?? {};
   return {
     canAdmin: currentUser && currentUser.access === 'admin',
   };