[NixOS] Move nixpkgs to avoid copying into my own flake source

My own flake source gets updated much more frequently

.gitmodules

@@ -11,5 +11,5 @@
 	path = nixos/home-manager
 	url = git@github.com:IvanMalison/home-manager.git
 [submodule "nixos/nixpkgs"]
-	path = nixos/nixpkgs
+	path = nixpkgs
 	url = git@github.com:IvanMalison/nixpkgs.git

nixos/flake.nix

@@ -3,7 +3,7 @@
     nixos-hardware = { url = github:NixOS/nixos-hardware; };
 
     nixpkgs = {
-      url = path:./nixpkgs;
+      url = path:../nixpkgs;
     };
 
     home-manager = {