Missing 1.26.6 extra images in registry-image-helper.sh

Similar to #488. OL9 OCNE1.7 [olcne-utils](https://yum.oracle.com/repo/OracleLinux/OL9/olcne17/x86_64/index.html) is missing Kubernetes v1.26.6 extra images.

Unfortunately, [installing Kubernetes module](https://docs.oracle.com/en/operating-systems/olcne/1.7/kubernetes/deploy-kube-intro.html#module-kube-report) always times out, so I'm forced to use a local registry.