[lille] remove VM 'users-api-alpha'

data/grid5000/sites/lille/servers/users-api-alpha.json

-{
-  "kind": "virtual",
-  "network_adapters": {
-    "default": {
-      "ip": "172.16.47.147"
-    }
-  },
-  "type": "server",
-  "uid": "users-api-alpha"
-}
\ No newline at end of file

input/grid5000/sites/lille/servers/virtual.yaml

@@ -261,6 +261,3 @@ elk:
   network_adapters:
     default:
       ip: 172.16.47.145
-users-api-alpha:
-  kind: virtual
-  network_adapters: {default: {ip: 172.16.47.147}}