amber: Fix build (#120126)

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

pkgs/tools/text/amber/default.nix

@@ -1,5 +1,5 @@
 { lib, stdenv, fetchFromGitHub, rustPlatform
-, Security
+, libiconv, Security
 }:
 
 rustPlatform.buildRustPackage rec {
@@ -15,7 +15,7 @@ rustPlatform.buildRustPackage rec {
 
   cargoSha256 = "sha256-opRinhTmhZxpAwHNiVOLXL8boQf09Y1NXrWQ6HWQYQ0=";
 
-  buildInputs = lib.optional stdenv.isDarwin Security;
+  buildInputs = lib.optionals stdenv.isDarwin [ libiconv Security ];
 
   meta = with lib; {
     description = "A code search-and-replace tool";