Error consistently during prospective prerender (#70631)
When `dynamicIO` is enabled there is a prospective render used to fill
caches. Previously we ignored errors during this phase. However this
might mask user errors that are flakey. With this change we consider
errors during the prospective render valid and throw them to the same
handling logic that handles errors for the final render. We exclude
control errors like prerender complete and prerender interrupted.
