bootkube: Update to stable-4.4 channel

Now that we are on 4.4 we need to update the default channel.

Author: smarterclayton

data/data/manifests/bootkube/cvo-overrides.yaml.template

@@ -5,5 +5,5 @@ metadata:
   name: version
 spec:
   upstream: https://api.openshift.com/api/upgrades_info/v1/graph
-  channel: stable-4.3
+  channel: stable-4.4
   clusterID: {{.CVOClusterID}}