pango: remove unnecessary gobject-introspection from buildInputs

Since #200337, it is propagated from nativeBuildInputs.

pkgs/development/libraries/pango/default.nix

···
   buildInputs = [
     fribidi
     libthai
-    gobject-introspection
   ] ++ lib.optionals stdenv.isDarwin (with darwin.apple_sdk.frameworks; [
     ApplicationServices
     Carbon