Revert "feat(niri,xbacklight): Brightness control"

This reverts commit 9b0e21d04d786116d2578cb4e4a526619e79a7c4.

modules/nixos/xbacklight-permissions.nix

@@ -1,35 +0,0 @@
-{ config, lib, pkgs, ... }:
-
-let cfg = config.sydnix.xbacklight-permissions;
-in {
-  options.sydnix.xbacklight-permissions = {
-    enable =
-      lib.mkEnableOption "the user group that is allowed to use xbacklight";
-    group = lib.mkOption {
-      type = lib.types.str;
-      default = "xbacklight";
-    };
-    paths = lib.mkOption {
-      type = with lib.types; listOf str;
-      default = [
-        "/sys/class/backlight/intel_backlight/brightness"
-      ];
-    };
-  };
-
-  config = lib.mkIf cfg.enable {
-    users.groups.${cfg.group} = {};
-
-    systemd.tmpfiles.settings."50-xbacklight" =
-      lib.mergeAttrsList
-        (builtins.map
-          (path: {
-            ${path}.z = {
-              inherit (cfg) group;
-              mode = "0664";
-              user = "root";
-            };
-          })
-          cfg.paths);
-  };
-}