[grenoble] vms : remove user VM pneyron-spack-vm

data/grid5000/sites/grenoble/servers/pneyron-spack-vm.json

-{
-  "expire": "2024-03",
-  "kind": "virtual",
-  "network_adapters": {
-    "default": {
-      "ip": "172.16.29.1"
-    }
-  },
-  "type": "server",
-  "uid": "pneyron-spack-vm"
-}
\ No newline at end of file

input/grid5000/sites/grenoble/servers/user-machines.yaml

-pneyron-spack-vm:
-  kind: virtual
-  expire: 2024-03
-  network_adapters: {default: {ip: 172.16.29.1}}
-
 orichard-nix-datamove:
   kind: physical
   alias: [nix-datamove]