ci: Deploy exactly `nWorker` worker machines
ci: Deploy exactly `nWorker` worker machines

Before, the `nWorker` variable in the infrastructure spec was misleading
because it actually deployed `nWorker + 1` worker machines.

LuiseV/quilt,kklin/quilt,kklin/kelda,kelda/kelda,PenguinToast/quilt,PenguinToast/quilt,quilt/quilt,tejasmanohar/quilt,NetSys/quilt,NetSys/quilt,kayousterhout/quilt,LuiseV/quilt,tejasmanohar/quilt,kayousterhout/quilt,kelda/kelda,PenguinToast/quilt,tejasmanohar/quilt,NetSys/quilt,ejj/quilt-dev,LuiseV/quilt,LuiseV/quilt,ejj/quilt-dev,PenguinToast/quilt,PenguinToast/quilt,kayousterhout/quilt,quilt/quilt,kayousterhout/quilt,kklin/quilt,tejasmanohar/quilt,kelda/kelda,ejj/quilt-dev,kklin/kelda,kklin/kelda,kelda/kelda,NetSys/quilt,quilt/quilt,NetSys/quilt,ejj/quilt-dev,kklin/kelda,quilt/quilt,LuiseV/quilt,kklin/quilt,kklin/quilt