bug#79714: env: always adds __CF_USER_TEXT_ENCODING var on macOS since v9.8

Pádraig Brady wrote:
> In fact only 6 commands require the localename-unsafe dependency:  date, du 
> through show-date() (fprintftime), and
>   ls, pr, stat, uptime through strftime().
> So I'll adjust things to only link those against CoreFoundation.

This will have no effect in most cases.

The CoreFoundation dependency is needed for two purposes:
  - Gnulib modules such as localename, nstrftime, fprintftime,
  - $(LIBINTL) when built without --disable-nls.
    Here, it ensures that the user's settings in control panels
    are respected by programs that, as usual, do
      setlocale (LC_ALL, "");

Since normally, on macOS, GNU packages are built with NLS enabled,
the 'env' program will still be linked against CoreFoundation.

Bruno