centroid: pin nixpkgs

flake.nix

@@ -58,6 +58,7 @@
         system = "x86_64-linux";
         modules = [
           self.nixosModules.beatific
+          (pinNixpkgs nixpkgs-2311)
           ./machine/centroid
         ];
       };

machine/centroid/default.nix

@@ -18,6 +18,7 @@
   };
 
   networking.networkmanager.enable = true;
+  users.users.tvb.extraGroups = [ "networkmanager" ];
 
   system.stateVersion = "23.11";
 }