fix: Kubernetes integration when using cgroups v2

[rossf7]

Hi @bpetit, I had a problem when testing with ubuntu:22.04 since it uses cgroups v2.

The paths are now relative so I needed to remove the ^ from the regex.

/../../../kubepods-besteffort.slice/kubepods-besteffort-pod43a7b130_2354_4564_9628_554d82403c6f.slice/cri-containerd-339bb32e778c77fcfdf986785997959e4519dfdca5b9100d06aa00685145ce85.scope

I also tested with ubuntu:20.04 to check compatibility with cgroups v1.