irc/ezbounce: Deprecate port (again)

This port has been marked broken for two-and-a-half months due to a
Boost update, does not build with modern compilers (now also GCC 15,
not just clang), is dead upstream with the last release 15 years ago.

So deprecate (again) with an expiration date in five weeks (= nearly
four months after being marked BROKEN).

PR: 281235