We have a few dependencies that are such a significant part of Terraform's
behavior that they will often be the root cause of or the solution to a
bug reported against Terraform.

As a small quality-of-life improvement to help with diagnosing those,
we'll now report the selected versions for each of these so-called
"interesting" dependencies as part of our initial trace log output during
Terraform startup.

The goal here is that when someone opens a bug report, and includes the
trace log as our bug report template requests, we'll be able to see at a
glance which versions of these dependencies were involved, instead of
having to manually cross-reference in the go.mod file of the reported main
Terraform CLI version.

This does slightly grow the general overhead of the logs, but as long as
we keep this set of interesting dependencies relatively small it shouldn't
present any significant problem in typical usage.