fix infinite recursion

lib/build-clan/default.nix

@@ -9,7 +9,6 @@
 {
   ## Inputs
   self ? null, # Reference to the current flake
-  directory ? null, # the directory containing the machines subdirectory. Optional: can be used if the machines is not in the root of the flake
   # allows to include machine-specific modules i.e. machines.${name} = { ... }
   # A map from arch to pkgs, if specified this nixpkgs will be only imported once for each system.
   # This improves performance, but all nipxkgs.* options will be ignored.
@@ -26,16 +25,9 @@ let
       lib
       nixpkgs
       clan-core
+      self
       ;
     inherit specialArgs;
-    self =
-      if self == null then
-        lib.warn "The buildClan function requires argument 'self' to be set to the current flake" {
-          inputs = { };
-        }
-      else
-        self;
-    directory = if directory == null then self else directory;
   };
 
   rest = builtins.removeAttrs attrs [ "specialArgs" ];