Boskos has been moved into its own repository under kubernetes-sigs:
https://github.com/kubernetes-sigs/boskos
The only thing matters here is ./cmd/janitor/gcp_janitor.py script, which is
still used by
/scenarios/kubernetes_janitor.py#L66,
and /scenarios had been announced deprecated since 2018, which will be done
with kubernetes#20760.