Vagrantfile.fedora: bump to 38

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

Vagrantfile.fedora

@@ -3,7 +3,7 @@
 
 Vagrant.configure("2") do |config|
 # Fedora box is used for testing cgroup v2 support
-  config.vm.box = "fedora/37-cloud-base"
+  config.vm.box = "fedora/38-cloud-base"
   config.vm.provider :virtualbox do |v|
     v.memory = 2048
     v.cpus = 2