macvim: Add -headerpad_max_install_names (#73592)

We were adding this to the compilation of MacVim, but not to the
compilation of the separate Vim binary. We may not actually need it for
MacVim at all, but omitting it for the Vim binary meant our postInstall
phase would fail for some people.

Fixes #73514

pkgs/applications/editors/vim/macvim.nix

@@ -76,6 +76,7 @@ stdenv.mkDerivation {
       "--with-tclsh=${tcl}/bin/tclsh"
       "--with-tlib=ncurses"
       "--with-compiledby=Nix"
+      "LDFLAGS=-headerpad_max_install_names"
   ];
 
   makeFlags = ''PREFIX=$(out) CPPFLAGS="-Wno-error"'';