homeConfigurations don't work with standalone home manager

overlays/nix-schemas/default.nix

@@ -1,19 +0,0 @@
-{
-  # Channels are named after NixPkgs instances in your flake inputs. For example,
-  # with the input `nixpkgs` there will be a channel available at `channels.nixpkgs`.
-  # These channels are system-specific instances of NixPkgs that can be used to quickly
-  # pull packages into your overlay.
-  channels,
-  inputs,
-  ...
-}: final: prev: {
-  nix-schemas = inputs.nix-schemas.packages.${prev.system}.nix.overrideAttrs (old: {
-    doCheck = false;
-    doInstallCheck = false;
-    postInstall =
-      old.postInstall or ""
-      + ''
-        mv $out/bin/nix $out/bin/nix-schemas
-      '';
-  });
-}