local-grid: Use upstream `vagrant-guest.nix`.

It looks like this may have been originally copied from a newer nixpkgs
since it wasn't in our nixpkgs fork.

The differences I can see:
- Details of `sudoer` file, some of which appear to be duplicates.
- `jq` and `gnumake` are not on the system path
- `vagrant` user is in group `users` instead of `vagrant`.

morph/lib/hardware-virtual.nix

 { publicIPv4, ... }:
+{ modulesPath, ... }:
 {
-  imports = [ ./vagrant-guest.nix ];
+  imports = [
+    # modulesPath points at the upstream nixos/modules directory.
+    "${modulesPath}/virtualisation/vagrant-guest.nix"
+  ];
 
   virtualisation.virtualbox.guest.enable = true;
 

morph/lib/vagrant-guest.nix

-# Minimal configuration that vagrant depends on
-
-{ config, pkgs, lib, ... }:
-let
-  # Vagrant uses an insecure shared private key by default, but we
-  # don't use the authorizedKeys attribute under users because it should be
-  # removed on first boot and replaced with a random one. This script sets
-  # the correct permissions and installs the temporary key if no
-  # ~/.ssh/authorized_keys exists.
-  install-vagrant-ssh-key = pkgs.writeScriptBin "install-vagrant-ssh-key" ''
-    #!${pkgs.runtimeShell}
-    if [ ! -e ~/.ssh/authorized_keys ]; then
-      mkdir -m 0700 -p ~/.ssh
-      echo "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA6NF8iallvQVp22WDkTkyrtvp9eWW6A8YVr+kz4TjGYe7gHzIw+niNltGEFHzD8+v1I2YJ6oXevct1YeS0o9HZyN1Q9qgCgzUFtdOKLv6IedplqoPkcmF0aYet2PkEDo3MlTBckFXPITAMzF8dJSIFo9D8HfdOV0IAdx4O7PtixWKn5y2hMNG0zQPyUecp4pzC6kivAIhyfHilFR61RGL+GPXQ2MWZWFYbAGjyiYJnAmCP3NOTd0jMZEnDkbUvxhMmBYSdETk1rRgm+R4LOzFUGaHqHDLKLX+FIPKcF96hrucXzcWyLbIbEgE98OHlnVYCzRdK8jlqm8tehUc9c9WhQ== vagrant insecure public key" >> ~/.ssh/authorized_keys
-      chmod 0600 ~/.ssh/authorized_keys
-    fi
-  '';
-in
-{
-  # Services to enable:
-
-  # Enable the OpenSSH daemon.
-  services.openssh.enable = true;
-
-  # Enable DBus
-  services.dbus.enable    = true;
-
-  # Replace ntpd by timesyncd
-  services.timesyncd.enable = true;
-
-  # Packages for Vagrant
-  environment.systemPackages = with pkgs; [
-    findutils
-    gnumake
-    iputils
-    jq
-    nettools
-    netcat
-    nfs-utils
-    rsync
-  ];
-
-  users.users.root = { password = "vagrant"; };
-
-  # Creates a "vagrant" group & user with password-less sudo access
-  users.groups.vagrant = {
-    name = "vagrant";
-    members = [ "vagrant" ];
-  };
-  users.extraUsers.vagrant = {
-    isNormalUser    = true;
-    createHome      = true;
-    group           = "vagrant";
-    extraGroups     = [ "users" "wheel" ];
-    password        = "vagrant";
-    home            = "/home/vagrant";
-    useDefaultShell = true;
-  };
-
-  systemd.services.install-vagrant-ssh-key = {
-    description = "Vagrant SSH key install (if needed)";
-    after = [ "fs.target" ];
-    wants = [ "fs.target" ];
-    wantedBy = [ "multi-user.target" ];
-    serviceConfig = {
-      ExecStart = "${install-vagrant-ssh-key}/bin/install-vagrant-ssh-key";
-      User = "vagrant";
-      # So it won't be (needlessly) restarted:
-      RemainAfterExit = true;
-    };
-  };
-
-  security.sudo.wheelNeedsPassword = false;
-
-  security.sudo.extraConfig =
-    ''
-      Defaults:root,%wheel env_keep+=LOCALE_ARCHIVE
-      Defaults:root,%wheel env_keep+=NIX_PATH
-      Defaults:root,%wheel env_keep+=TERMINFO_DIRS
-      Defaults env_keep+=SSH_AUTH_SOCK
-      Defaults lecture = never
-      root   ALL=(ALL) SETENV: ALL
-      %wheel ALL=(ALL) NOPASSWD: ALL, SETENV: ALL
-    '';
-}
-