crun 1.4.3 as well as runc 1.1 both support to open bind-mounts before
dropping privileges, as they are inaccessible after switching to the
user namespace. So that is the minimum version to use with containerd
1.7.
Also, since containerd 2.0 we use idmap mounts for files mounted in the
container created by containerd (like etc/hostname, etc/hosts, etc.), so
in that case we require newer OCI runtimes too. However, as the kubelet
doesn't request idmap mounts for kube volumes, we can lower the kernel
version.
Signed-off-by: Rodrigo Campos <rodrigoca@microsoft.com>