[Perl/perl5] b8b94c: Avoid using ' version of isnt

[Nicolas Mendoza via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: b8b94c781ed48848fca6808550710df53c2ef4e9
      
https://github.com/Perl/perl5/commit/b8b94c781ed48848fca6808550710df53c2ef4e9
  Author: Nicolas Mendoza <mend...@pvv.ntnu.no>
  Date:   2022-06-15 (Wed, 15 Jun 2022)

  Changed paths:
    M dist/PathTools/t/tmpdir.t

  Log Message:
  -----------
  Avoid using ' version of isnt