Upgrade 4.13 cluster to latest/stable (5.18) hung because of clustering_server_cert_trust

All nodes are hanging with same information.

2023-10-12T01:35:35-04:00 lxd.daemon[2431682]: time=“2023-10-12T01:35:35-04:00” level=warning msg=“Waiting for "clustering_server_cert_trust" patch to be applied on all cluster members”

LXD is no longer part of the Linux Containers project, support for it is provided on the Ubuntu Discourse these days.