generalize nspawn network config

hosts/thinkpad/modules/virtualisation/default.nix

@@ -27,20 +27,26 @@
     virt-viewer
     podman-compose
   ];
-  systemd.nspawn = {
+  systemd.nspawn =
-    n1 = {
+    let
       networkConfig = {
         Private = true;
         VirtualEthernet = true;
         Bridge = "br0";
       };
-    };
+    in
-    n2 = {
+    {
-      networkConfig = {
+      n1 = {
-        Private = true;
+        inherit networkConfig;
-        VirtualEthernet = true;
+      };
-        Bridge = "br0";
+      n2 = {
+        inherit networkConfig;
+      };
+      evpn1 = {
+        inherit networkConfig;
+      };
+      evpn2 = {
+        inherit networkConfig;
       };
     };
-  };
 }