Update kubernetes cgroup value for libvirt

The reason for this PR is that in most cases
we utilize systemd cgroup driver nowadays.
So it worth it to set kubepods.slice cgroup root
by default.

https: //github.com/kubernetes/kubernetes/blob/release-1.26/pkg/kubelet/cm/cgroup_manager_linux.go#L77-L81
Change-Id: I0cad148eb827439815c7e5bad1d6b6108cd1ab8d

libvirt/Chart.yaml

@@ -15,7 +15,7 @@ apiVersion: v1
 appVersion: v1.0.0
 description: OpenStack-Helm libvirt
 name: libvirt
-version: 0.1.18
+version: 0.1.19
 home: https://libvirt.org
 sources:
   - https://libvirt.org/git/?p=libvirt.git;a=summary

libvirt/values.yaml

@@ -119,7 +119,7 @@ conf:
     user: "nova"
     group: "kvm"
   kubernetes:
-    cgroup: "kubepods"
+    cgroup: "kubepods.slice"
 
 pod:
   probes:

releasenotes/notes/libvirt.yaml

@@ -19,4 +19,5 @@ libvirt:
   - 0.1.16 Update all Ceph images to Focal
   - 0.1.17 Add ovn.yaml values_override, remove dependency from neutron-ovs-agent module
   - 0.1.18 Replace node-role.kubernetes.io/master with control-plane
+  - 0.1.19 Set kubernetes cgroup value equal kubepods.slice to fit systemd cgroup driver
 ...