Define custom networks with OPACK_VAGRANT_NETWORK override

src/vagrantfile.mk

@@ -12,6 +12,7 @@ Vagrant.configure("2") do |config|
   config.ssh.sudo_command = "doas env %c"
   config.vm.synced_folder ".", "/vagrant", disabled: true
   config.vm.provision "shell", path: "$(OPACK_RUNTIME_PROVISION_FILE)"
+  $(OPACK_VAGRANT_NETWORK)
   config.vm.provider "libvirt" do |l|
     l.cpus = $(OPACK_SYS_CPU)
     l.memory = $(OPACK_SYS_MEMORY)