[Perl/perl5] 361850: silence warning in svleak.t

[iabyn via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 361850e25fd106bc1f68b0ee5549e32df4bc041c
      
https://github.com/Perl/perl5/commit/361850e25fd106bc1f68b0ee5549e32df4bc041c
  Author: David Mitchell <da...@iabyn.com>
  Date:   2023-09-02 (Sat, 02 Sep 2023)

  Changed paths:
    M t/op/svleak.t

  Log Message:
  -----------
  silence warning in svleak.t

A recently added smartmatch test was triggering a 'deprecated' warning.