Add removal of cache after 7 days

nixos/EDI/configuration.nix

@@ -50,6 +50,11 @@
   };
 
   nix = {
+    gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 7d";
+    };
     # This will add each flake input as a registry
     # To make nix3 commands consistent with your flake
     registry = lib.mapAttrs (_: value: {flake = value;}) inputs;