fix: update NixOS channel references to version 25.05 and adjust netdata configuration

utils/modules/netdata.nix

@@ -1,10 +1,14 @@
-{ config, pkgs, ... }:
+{ config, lib, pkgs, ... }:
 let
   unstable = import (fetchTarball https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz) {
     config = { allowUnfree = true; };
   };
 in
 {
+  nixpkgs.config.allowUnfreePredicate = pkg: builtins.elem (lib.getName pkg) [
+    "netdata"
+  ];
+
   services.netdata.configDir."python.d.conf" = pkgs.writeText "python.d.conf" ''
     postfix: yes
   '';
@@ -14,7 +18,7 @@ in
     python.enable = true;
 
     package = pkgs.netdata.override {
-      withCloud = true;
+      withCloudUi = true;
     };
 
     config = {