Update image volume example to use v2

Use the `v2` version of the artifact to allow compatibility with
containerd.

Signed-off-by: Sascha Grunert <[email protected]>

Author: saschagrunert

content/en/examples/pods/image-volumes-subpath.yaml

@@ -14,5 +14,5 @@ spec:
   volumes:
   - name: volume
     image:
-      reference: quay.io/crio/artifact:v1
+      reference: quay.io/crio/artifact:v2
       pullPolicy: IfNotPresent

content/en/examples/pods/image-volumes.yaml

@@ -13,5 +13,5 @@ spec:
   volumes:
   - name: volume
     image:
-      reference: quay.io/crio/artifact:v1
+      reference: quay.io/crio/artifact:v2
       pullPolicy: IfNotPresent