Migrated from import based to config based

modules/system/services/garbage-collection.nix

@@ -0,0 +1,26 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.settings.services.garbage-collection;
+in {
+  options = {
+    settings.services.garbage-collection.enable = lib.mkOption {
+      type = lib.types.bool;
+      description = ''
+        Enable garbage collection of nix store
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    nix.gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 1w";
+    };
+
+    nix.settings.auto-optimise-store = true;
+  };
+}