Test configuration

modules/nixos/garbage-collection.nix

@@ -0,0 +1,8 @@
+{
+  nix.settings.auto-optimise-store = true; # Deduplicates files
+  nix.gc = {
+    automatic = true;
+    dates = "weekly";
+    options = "--delete-older-than 30d";
+  };
+}