Disable IPv6 support for canal's calico-node (#5684)

This implements the same behavior as https://github.com/kubernetes-sigs/kubespray/blob/a15a0b5eb954c29636b4257463ef29ab2f5a191c/roles/network_plugin/calico/templates/calico-node.yml.j2

More info: https://github.com/projectcalico/felix/issues/1447

roles/network_plugin/canal/templates/canal-node.yaml.j2

@@ -224,6 +224,9 @@ spec:
             - name: FELIX_IPTABLESLOCKTIMEOUTSECS
               value: "10"
 {% endif %}
+            # Disable IPv6 on Kubernetes.
+            - name: FELIX_IPV6SUPPORT
+              value: "false"
             # Etcd SSL vars
             - name: ETCD_CA_CERT_FILE
               valueFrom: