fix(ssr): fix transform error due to export all id scope

[hi-ogawa]

Description

• Closes can not use export * as variable from "./somefile" and import * as variable from "./somefile" in same file with vite v6 #19329
• Closes can not use export * as variable from "./somefile" and import * as variable from "./somefile" in same file with vite v6 vitest-dev/vitest#7394

Even on Vite 5, SSR transform wasn't properly handling the identifier from export * as id from ".." as seen by the same repro https://stackblitz.com/edit/github-pnyojxdr-mena4fdt?file=repro-vite.js

const __vite_ssr_import_0__ = await __vite_ssr_import__('x');

const __vite_ssr_import_1__ = await __vite_ssr_import__('x');

Object.defineProperty(__vite_ssr_exports__, 'x', {
  enumerable: true,
  configurable: true,
  get() {
    return __vite_ssr_import_1__;
  },
});
__vite_ssr_import_0__; /// <-- what's this?

I haven't investigated why this now causes magic-string error, but this can be fixed by fixing isRefIdentifier to skip identifiers inside export * ....