networking: use networkd

otherwise we would need to add each interface individually, which is
quite difficult without stable interface names.

So let's use networkd, which is overall the better solution anyway.

Author: Mic92

modules/nixos/networking/default.nix

@@ -4,7 +4,8 @@
     ./broadcom.nix
     ./intel.nix
   ];
-  config.networking = lib.mkIf (builtins.length (config.facter.report.network_interface or [ ]) > 0) {
-    useDHCP = lib.mkDefault true;
+  config = lib.mkIf (builtins.length (config.facter.report.network_interface or [ ]) > 0) {
+    networking.useDHCP = lib.mkDefault true;
+    networking.useNetworkd = lib.mkDefault true;
   };
 }