update ci fedora 38

Signed-off-by: Kay Yan <[email protected]>

hack/ci/Vagrantfile

@@ -3,17 +3,13 @@
 
 # Vagrant box for testing kind with cgroup v2
 Vagrant.configure("2") do |config|
-  # `config.vm.box = "fedora/37-cloud-base"` seems flaky,
-  # so we specify the URL explicitly.
-  # Mirrors can be found at here: https://admin.fedoraproject.org/mirrormanager/mirrors/Fedora/37/x86_64
-  config.vm.box = "dummy"
-  config.vm.box_url = "https://iad.mirror.rackspace.com/fedora/releases/37/Cloud/x86_64/images/Fedora-Cloud-Base-Vagrant-37-1.7.x86_64.vagrant-virtualbox.box"
+  config.vm.box = "fedora/38-cloud-base"
   # macOS github actions runners have 3 cores and 14 GB of ram
   # assume some ram is needed for the host environment but very little CPU
   # https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners
   memory = 10240
   cpus = 3
-  config.vm.provider :virtualbox do |v|
+  config.vm.provider :libvirt do |v|
     v.memory = memory
     v.cpus = cpus
   end