Ubuntu: containerd configuration issue with image-builder v0.1.31

[dalees]

In image-builder v0.1.31 my patch has merged kubernetes-sigs/image-builder#1501

However, this chart already configures this for ubuntu(not flatcar): https://github.com/azimuth-cloud/capi-helm-charts/blob/main/charts/openstack-cluster/templates/_helpers.tpl#L213-L221

With both of these in place the containerd configuration file ends up with a duplicate which containerd doesn't cope with, which @waipeng encountered:

systemd[1]: Starting containerd container runtime...
containerd[2801]: containerd: failed to load TOML: /etc/containerd/config.toml: (19, 2): duplicated tables
systemd[1]: containerd.service: Main process exited, code=exited, status=1/FAILURE