labtunnel: Remove labtunnel v1

Labtunnel has been moved to the `dev-util` project,
where it has been remade as a go-based CLI utility
instead of a bash one like this. This change deletes
this now outdated labtunnel v1.

Deleting was chosen over deprecation as it's not
expected that anyone still uses this version and there
is no reason not to move to v2.

BUG=None
TEST=None

Change-Id: Ic1326afe1d59eba2c6f9baa6e2b47709c7acf2dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/3894817
Tested-by: Jared Bennett <jaredbennett@google.com>
Reviewed-by: Shijin Abraham <shijinabraham@google.com>
Commit-Queue: Jared Bennett <jaredbennett@google.com>
5 files changed