Revert "flake.nix: Set nixpkgs.config.path"

This reverts commit 0b222173db.

flake.nix

@@ -48,10 +48,6 @@
                   system.nixos.versionSuffix =
                     ".${final.substring 0 8 (self.lastModifiedDate or self.lastModified or "19700101")}.${self.shortRev or "dirty"}";
                   system.nixos.revision = final.mkIf (self ? rev) self.rev;
-
-                  # NOTE: This assumes that `nixpkgs.config` is _not_ used when
-                  #       nixpkgs.pkgs is set OR _module.args.pkgs is set.
-                  nixpkgs.config.path = self.outPath;
                 }
               ];
           });

nixos/modules/misc/nixpkgs.nix

@@ -59,8 +59,6 @@ let
     inherit (cfg) config overlays localSystem crossSystem;
   };
 
-  # NOTE: flake.nix assumes that nixpkgs.config is only used with ../../..
-  #       as nixpkgs.config.path should be equivalent to ../../..
   finalPkgs = if opt.pkgs.isDefined then cfg.pkgs.appendOverlays cfg.overlays else defaultPkgs;
 
 in