generator: remove unused test types

We never used moblab_vm tests, and tast_vm has been replaced with
direct_tast_vm

https://crrev.com/i/3282004 is the corresponding config change.

Bug: 1130018
Change-Id: Ic6bcbf840b8572bdd4656bcfed340bb277c6faf8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/go/+/2421420
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Sean Abraham <seanabraham@chromium.org>
Tested-by: Sean Abraham <seanabraham@chromium.org>
2 files changed