gnatcoll-python3: fix build on x86_64-darwin

pkgs/development/libraries/ada/gnatcoll/bindings.nix

···
 , zlib
 , python3
 , ncurses
+, darwin
 }:
 
 let
···
     gprbuild
     gnat
     python3
+  ];
+
+  buildInputs = lib.optionals stdenv.isDarwin [
+    darwin.apple_sdk.frameworks.CoreFoundation
   ];
 
   # propagate since gprbuild needs to find referenced .gpr files