cleanup: Drop no longer used cluster

cluster-configuration/values/archive-staging.yaml

-clusterName: archive-staging
-clusterUrl: https://rancher.euwest.azure.internal.softwareheritage.org/k8s/clusters/c-cx2bq
-
-metallb:
-  enabled: true
-
-ingressNginx:
-  enabled: true
-  defaultClass: true
-  annotations:
-    # To be able to share the same ip for several services
-    # https://metallb.org/usage/#ip-address-sharing
-    metallb.universe.tf/allow-shared-ip: clusterIP
-
-certManager:
-  enabled: true
-  webhookGandiEnabled: true
-  useGandiDNS: true