[Perl/perl5] 800cef: locale.c: Use sv_setsv_nomg() over SvSetSV()

[Karl Williamson via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 800cef83424dbe60b8c9dbd98997f526e902a0da
      
https://github.com/Perl/perl5/commit/800cef83424dbe60b8c9dbd98997f526e902a0da
  Author: Karl Williamson <k...@cpan.org>
  Date:   2024-01-21 (Sun, 21 Jan 2024)

  Changed paths:
    M locale.c

  Log Message:
  -----------
  locale.c: Use sv_setsv_nomg() over SvSetSV()

This avoids checking for magic and that the source and destination
aren't the same.  We know here these are not the case.