[Perl/perl5] a808d7: [doc] Update File::Basename synopsis

[Elvin Aslanov via perl5-changes]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: a808d73686a9dab311eeb27f981eb4a61c43a108
      
https://github.com/Perl/perl5/commit/a808d73686a9dab311eeb27f981eb4a61c43a108
  Author: Elvin Aslanov <rwp.prim...@gmail.com>
  Date:   2022-08-30 (Tue, 30 Aug 2022)

  Changed paths:
    M lib/File/Basename.pm

  Log Message:
  -----------
  [doc] Update File::Basename synopsis

Add `my` on examples.