We previously would optimize away the graph nodes for any resource
instance without a real change pending, but that means we don't get an
opportunity to re-check any invariants associated with the instance, such
as preconditions and postconditions.
Other upstream changes during apply can potentially decide the outcome of
a condition even if the instance itself isn't being changed, so we do
still need to revisit these during apply or else we might skip running
certain checks altogether, if they yielded unknown results during planning
and then don't get run during apply.
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.
If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
