Expand disk size of Vagrant box for libvirt provider

Vagrantfile

Vagrant.configure("2")  do |config|

  config.vm.define :server do |server|
    server.vm.box = "rockylinux/8"
    server.vm.box_version = "4.0.0"
    server.vm.hostname = "warewulf-server"

    server.vm.network "private_network",
      ip: "10.0.0.254",
      netmask: "255.255.252.0",
      libvirt__network_name: "pxe",
      libvirt__dhcp_enabled: false

    server.vm.provider :libvirt do |libvirt|
      libvirt.cpu_mode = "host-passthrough"
      libvirt.memory = '4192'
      libvirt.cpus = '2'
      libvirt.machine_virtual_size = 40
    end

    server.vm.provision "shell", inline: <<-SHELL
      dnf install -y cloud-utils-growpart
      growpart /dev/vda 1
      xfs_growfs /dev/vda1
    SHELL

  end
end