adding nix-builders

systems/jeeves/runner.nix

@@ -20,5 +20,8 @@
     nix-builder-0.enable = true;
     nix-builder-1.enable = true;
     nix-builder-2.enable = true;
+    nix-builder-3.enable = true;
+    nix-builder-4.enable = true;
+    nix-builder-5.enable = true;
   };
 }