Please update pod/perldelta.pod for 5.33.6

Hi Porters,

I'm aiming to release v5.33.6 on Jan 20th. There have been over 150 commits
to blead since 5.33.5, but only 3 updates made to perldelta.pod.

If you have made any commits/PRs that warrant inclusion in perldelta.pod,
please update this file with a summary of your changes, ideally by the end
of Monday (18th). I'll be reviewing the commits myself later this week.

Many Thanks,
Richard

• Please update pod/perldelta.pod for 5.33.6 by Richard Leach