[Perl/perl5] ed4b2b: locale.c: Stop compiler warning

[Karl Williamson via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: ed4b2b05d25c19e1c2271b7f125531933fdab5aa
      
https://github.com/Perl/perl5/commit/ed4b2b05d25c19e1c2271b7f125531933fdab5aa
  Author: Karl Williamson <k...@cpan.org>
  Date:   2022-09-25 (Sun, 25 Sep 2022)

  Changed paths:
    M embed.fnc
    M embed.h
    M locale.c
    M proto.h

  Log Message:
  -----------
  locale.c: Stop compiler warning

S_less_dicey_bool_setlocale_r() is a short function that makes a
complete set of similar functions, but there is no current use of it.
So just #ifdef it out.

This resolves #20338