Ensure generateStaticParams works in route (#46310)
x-ref: [slack
thread](https://vercel.slack.com/archives/C04DUD7EB1B/p1677165000745519)
## Bug
- [ ] Related issues linked using `fixes #number`
- [ ] Integration tests added
- [ ] Errors have a helpful link attached, see
[`contributing.md`](https://github.com/vercel/next.js/blob/canary/contributing.md)
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Co-authored-by: Jimmy Lai <laijimmy0@gmail.com>
