Fix import of use-sync-external-store

Author: eddyw

packages/react/src/index.ts

@@ -8,7 +8,7 @@ import {
 import React from "react";
 import jsxRuntime from "react/jsx-runtime";
 import jsxRuntimeDev from "react/jsx-dev-runtime";
-import { useSyncExternalStore } from "use-sync-external-store/shim";
+import { useSyncExternalStore } from "use-sync-external-store/shim/index.js";
 import {
 	signal,
 	computed,