nixos: use experimental nixos-rebuild-ng

Flake lock file updates:

• Updated input 'nixos-unstable':
    'github:NixOS/nixpkgs/ee930f9755f58096ac6e8ca94a1887e0534e2d81' (2025-06-13)
  → 'github:NixOS/nixpkgs/9e83b64f727c88a7711a2c463a7b16eedb69a84c' (2025-06-17)
• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/6c64dabd3aa85e0c02ef1cdcb6e1213de64baee3' (2025-06-15)
  → 'github:NixOS/nixpkgs/36ab78dab7da2e4e27911007033713bab534187b' (2025-06-17)
• Updated input 'nur':
    'github:nix-community/NUR/a08f1cd495f510a4e8f87c69165970bd97fdd84e' (2025-06-09)
  → 'github:nix-community/NUR/b44e74a3ca2f9ab75d4ad7cecc52a052faae9871' (2025-06-19)
• Updated input 'nur/nixpkgs':
    'github:nixos/nixpkgs/3e3afe5174c561dee0df6f2c2b2236990146329f' (2025-06-07)
  → 'github:nixos/nixpkgs/9e83b64f727c88a7711a2c463a7b16eedb69a84c' (2025-06-17)

common/default.nix

@@ -269,4 +269,5 @@ in
   networking.networkmanager.unmanaged = [ "interface-name:ve-*" ];
 
   services.dbus.implementation = "broker";
+  system.rebuild.enableNg = true;
 }

flake.lock

@@ -195,11 +195,11 @@
     },
     "nixos-unstable": {
       "locked": {
-        "lastModified": 1749794982,
-        "narHash": "sha256-Kh9K4taXbVuaLC0IL+9HcfvxsSUx8dPB5s5weJcc9pc=",
+        "lastModified": 1750134718,
+        "narHash": "sha256-v263g4GbxXv87hMXMCpjkIxd/viIF7p3JpJrwgKdNiI=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "ee930f9755f58096ac6e8ca94a1887e0534e2d81",
+        "rev": "9e83b64f727c88a7711a2c463a7b16eedb69a84c",
         "type": "github"
       },
       "original": {
@@ -243,11 +243,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1750005367,
-        "narHash": "sha256-h/aac1dGLhS3qpaD2aZt25NdKY7b+JT0ZIP2WuGsJMU=",
+        "lastModified": 1750133334,
+        "narHash": "sha256-urV51uWH7fVnhIvsZIELIYalMYsyr2FCalvlRTzqWRw=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6c64dabd3aa85e0c02ef1cdcb6e1213de64baee3",
+        "rev": "36ab78dab7da2e4e27911007033713bab534187b",
         "type": "github"
       },
       "original": {
@@ -259,11 +259,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1749285348,
-        "narHash": "sha256-frdhQvPbmDYaScPFiCnfdh3B/Vh81Uuoo0w5TkWmmjU=",
+        "lastModified": 1750134718,
+        "narHash": "sha256-v263g4GbxXv87hMXMCpjkIxd/viIF7p3JpJrwgKdNiI=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "3e3afe5174c561dee0df6f2c2b2236990146329f",
+        "rev": "9e83b64f727c88a7711a2c463a7b16eedb69a84c",
         "type": "github"
       },
       "original": {
@@ -280,11 +280,11 @@
         "treefmt-nix": "treefmt-nix"
       },
       "locked": {
-        "lastModified": 1749502672,
-        "narHash": "sha256-FXobF6TY9wpMrXTfgO52LcKOg7VK1wjaexc1k/9ybpg=",
+        "lastModified": 1750318896,
+        "narHash": "sha256-bf+0tbn3Oq72jZ+3MpKbQL6ZEjkz9BbZJFWHBWawphc=",
         "owner": "nix-community",
         "repo": "NUR",
-        "rev": "a08f1cd495f510a4e8f87c69165970bd97fdd84e",
+        "rev": "b44e74a3ca2f9ab75d4ad7cecc52a052faae9871",
         "type": "github"
       },
       "original": {