selectors: Make sure EpollSelecrtor.select() works when no FD is registered.

Closes issue #23009.
selectors: Make sure EpollSelecrtor.select() works when no FD is registered.

Closes issue #23009.
selectors: Fix typo in comment.
selectors: Fix typo in comment.
NEWS: Add news entry for issue #23009.
NEWS: Add news entry for issue #23009.
NEWS: Remove duplicate entry
null merge with 3.4.