Do I need to remove fleet-system when removing k3s cluster from Rancher?

I’m replacing Rancher manager 2.5.17 in a vm with 2.7.1 in a docker container. The first thing that I’m doing is removing the cluster from the old Rancher. I know I need to delete the cattle-system namespace , and I’ve done that. But there is another namespace called “fleet-manager” which I don’t know the origin of.

Did k3s create that namespace? Or did Rancher create it when I imported the cluster? I google searched the namespace and didn’t find any conclusive answers, so I thought that I would ask here.