refactor: remove some layers of indirection

Author: hraban

Diff for: default.nix

@@ -8,6 +8,5 @@ let
     sha256 = sourceInfo.narHash;
   };
   flake = (prev.callPackage flake-compat { src = ./inputs; }).defaultNix;
-  lisp-overlay = import ./lisp-packages-lite.nix { inherit (flake) inputs; };
 in
-lisp-overlay final prev
+import ./lisp-packages-lite.nix { inherit (flake) inputs; pkgs = prev; }

Diff for: lisp-packages-lite.nix

@@ -14,16 +14,15 @@
 
 {
   inputs
+, pkgs
 , lisp ? pkgs: pkgs.sbcl
 }:
 
-# Return an overlay
-_: pkgs:
 with {
   inherit (pkgs) lib;
 };
 
-let
+{
   lispPackagesLite = lib.recurseIntoAttrs (lib.makeScope pkgs.newScope (self:
     with self;
     with callPackage ./utils.nix {};
@@ -2274,5 +2273,4 @@ let
 
     zpng = callPackage (self: with self; lispify "zpng" [ salza2 ]) {};
   }));
-in
-{ inherit lispPackagesLite; }
+}