Fix missing revalidate with notFound() (#75009)
This is follow-up to https://github.com/vercel/next.js/pull/74607
ensuring we also don't lose the revalidate value configured when
`notFound()` or similar is used.
x-ref: [slack
thread](https://vercel.slack.com/archives/C02K2HCH5V4/p1736954974909349)
