[Perl/perl5] a34095: io/open.t - add test for $! to pipe close

[Yves Orton via perl5-changes]

  Branch: refs/heads/yves/open_stdio_hpux_test_issue
  Home:   https://github.com/Perl/perl5
  Commit: a3409509c7a3c68798613656202bd600034acdd3
      
https://github.com/Perl/perl5/commit/a3409509c7a3c68798613656202bd600034acdd3
  Author: Yves Orton <demer...@gmail.com>
  Date:   2023-03-31 (Fri, 31 Mar 2023)

  Changed paths:
    M t/io/open.t

  Log Message:
  -----------
  io/open.t - add test for $! to pipe close

these fail on HPUX under PERLIO=stdio, hopefully this will help
us understand why.