Instant Validation: Allow unconfigured slots to render optionally (#92126)
When validating an instant navigation we always report blocking data
regardless of which parallel slot it was found from because it will
block the navigation regardless. To prevent accidental disabling of
validation Next.js also requires that the expected validation boundary
is actually rendered during the validation SSR pass. if it isn't it is
considered an error. However it is not uncommon to have a slot that only
renders conditionally. If during validation a slot is not rendered but
that slot also does not explicitly have an instant config it is now
considered allowable and no error is presented.
next.js
76df801a - Instant Validation: Allow unconfigured slots to render optionally (#92126)
