irc/miau: Deprecate and set expiration date to 2024-04-30

Abandoned upstream, last release in 2010 and no activity since 2014.
Redirect users to irc/soju or irc/znc

PR:		277298
Approved by:	portmgr (maintainer timeout, 3+ weeks)

irc/miau/Makefile

@@ -8,6 +8,9 @@ MAINTAINER=	freebsd-ports@dan.me.uk
 COMMENT=	Fully featured easy to use IRC-bouncer
 WWW=		https://miau.sourceforge.net/
 
+DEPRECATED=	Abandoned upstream, last release in 2010 and no activity since 2014. Consider migrating to irc/soju or irc/znc
+EXPIRATION_DATE=2024-04-30
+
 USES=		iconv tar:bzip2
 GNU_CONFIGURE=	yes
 GNU_CONFIGURE_MANPREFIX=${PREFIX}/share