fix NIX_CONFIG overridden in cicero job

The bug was introduced in e9dc3a1
but was not noticed until 5e224be
as that caused the nix sandbox to fail.

Author: dermetfan

nix/cloud/nomadEnvs/cicero/default.nix

@@ -57,7 +57,7 @@
             .job |= (
               .Datacenters += $args.datacenters |
               .TaskGroups[]?.Tasks[]? |= (
-                .Env += {
+                .Env |= . + {
                   NOMAD_ADDR: env.NOMAD_ADDR,
                   NOMAD_TOKEN: env.NOMAD_TOKEN,
                   CICERO_WEB_URL: $args.ciceroWebUrl,