lib/lxc-container: build a static /etc/resolv.conf instead of using resolvconf

lib/lxc-container.nix

@@ -1,4 +1,4 @@
-{ pkgs, lib, modulesPath, ... }:
+{ config, pkgs, lib, modulesPath, ... }:
 
 {
   imports = [
@@ -8,6 +8,9 @@
 
   networking.networkmanager.dns = "unbound";
   networking.useHostResolvConf = false;
+  environment.etc."resolv.conf".text = ''
+    nameserver ${builtins.concatStringsSep " " config.networking.nameservers}
+  '';
 
   nix.useSandbox = false;
   nix.maxJobs = lib.mkDefault 1;