tailscaled: after NetworkManager-wait-online

The wait will only be enabled on machines with NetworkManager enabled.

Closes NixOS#180175

(cherry picked from commit 0d822cc)

nixos/modules/services/networking/tailscale.nix

@@ -88,6 +88,7 @@ in {
     environment.systemPackages = [ cfg.package ]; # for the CLI
     systemd.packages = [ cfg.package ];
     systemd.services.tailscaled = {
+      after = lib.mkIf (config.networking.networkmanager.enable) [ "NetworkManager-wait-online.service" ];
       wantedBy = [ "multi-user.target" ];
       path = [
         pkgs.procps     # for collecting running services (opt-in feature)