crypto/internal/fips140: make Version return latest when not frozen

crypto/internal/fips140: make Version return latest when not frozen

Fixes #71820

Change-Id: I6a6a46563da281a7b20efc61eefdcbb2e146db33
Reviewed-on: https://go-review.googlesource.com/c/go/+/655795
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Daniel McCarney <daniel@binaryparadox.net>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>