Fix app ISR error handling (#57332)
This ensures when an error occurs during a revalidate in app router that
properly throw the error fully and don't store the error page in the
cache which matches the expected behavior for full route ISR as errors
are not meant to update the cache so that the last successful cache
entry can continue being served.
Fix was tested against the provided reproduction here
https://app-dir-example-ghl01cxtn-basement.vercel.app/
Fixes: https://github.com/vercel/next.js/issues/53195
