test: consolidate action flaky test (#65541)
This test failed in dev. It has 2 problems:
1. the nanoid only contains named export
2. we should wait for the content changed then check the browser url
```
● app-dir action handling › fetch actions › should handle redirects to routes that provide an
invalid RSC response
expect(received).toBe(expected) // Object.is equality
Expected: "http://localhost:50473/pages-dir"
Received: "http://localhost:50473/client"
891 |
892 | await retry(async () => {
> 893 | expect(await browser.url()).toBe(`${next.url}/pages-dir`)
```
Closes NEXT-3369
