nixos/nebula: Add nebula module and unit test to lists

nixos/modules/module-list.nix

@@ -699,6 +699,7 @@
   ./services/networking/nar-serve.nix
   ./services/networking/nat.nix
   ./services/networking/ndppd.nix
+  ./services/networking/nebula.nix
   ./services/networking/networkmanager.nix
   ./services/networking/nextdns.nix
   ./services/networking/nftables.nix

nixos/tests/all-tests.nix

@@ -250,6 +250,7 @@ in
   nat.standalone = handleTest ./nat.nix { withFirewall = false; };
   ncdns = handleTest ./ncdns.nix {};
   ndppd = handleTest ./ndppd.nix {};
+  nebula = handleTest ./nebula.nix {};
   neo4j = handleTest ./neo4j.nix {};
   netdata = handleTest ./netdata.nix {};
   networking.networkd = handleTest ./networking.nix { networkd = true; };