Revert "pkgs/top-level: add assert to prevent passing elaborated systems"

This reverts commit 434e36ab91.

pkgs/top-level/all-packages.nix

@@ -1669,9 +1669,9 @@ with pkgs;
   #     pkgsCross.aarch64-multiplatform.freshBootstrapTools.build
   freshBootstrapTools = if stdenv.hostPlatform.isDarwin then
     callPackage ../stdenv/darwin/make-bootstrap-tools.nix {
-      localSystem = { config = lib.systems.parse.tripleFromSystem stdenv.buildPlatform; };
+      localSystem = stdenv.buildPlatform;
       crossSystem =
-        if stdenv.buildPlatform == stdenv.hostPlatform then null else { config = lib.systems.parse.tripleFromSystem stdenv.hostPlatform; };
+        if stdenv.buildPlatform == stdenv.hostPlatform then null else stdenv.hostPlatform;
     }
   else if stdenv.hostPlatform.isLinux then
     callPackage ../stdenv/linux/make-bootstrap-tools.nix {}

pkgs/top-level/default.nix

@@ -46,11 +46,6 @@
   ...
 } @ args:
 
-# Passing fully elaborated systems to localSystem or crossSystem will break composability
-# of package sets.
-assert builtins.isAttrs localSystem -> !(localSystem ? parsed);
-assert builtins.isAttrs crossSystem -> !(crossSystem ? parsed);
-
 let # Rename the function arguments
   config0 = config;
   crossSystem0 = crossSystem;