internal/trace/internal/testgen: make generated trace version configurable
Replace hard coded references to version.Go122 with the trace version
passed to NewTrace. This allows writing testgen tests for newer trace
versions.
For #69869
Change-Id: Id25350cea1c397a09ca23465526ff259e34a4752
Reviewed-on: https://go-review.googlesource.com/c/go/+/653875
Auto-Submit: Michael Knyszek <mknyszek@google.com> Reviewed-by: Michael Knyszek <mknyszek@google.com> Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>