dns/djbdns: Deprecate and set expiration date to 2023-06-30

Project hasn't been centrally managed since last release in 2001 and
there are various third party patches to keep it somewhat relevant with
todays standards. Port has also been unmaintained since last
maintainer stepped down several months ago.

PR:		256450

dns/djbdns/Makefile

@@ -19,6 +19,9 @@ LICENSE_NAME=	djb
 LICENSE_TEXT=	No license -- see http://cr.yp.to/softwarelaw.html
 LICENSE_PERMS=	dist-mirror dist-sell pkg-mirror pkg-sell auto-accept
 
+DEPRECATED=	No longer compliant with current DNS standards and source code hasn't been centrally managed for over 20 years
+EXPIRATION_DATE=2023-06-30
+
 RUN_DEPENDS=	setuidgid:sysutils/daemontools \
 		tcpserver:sysutils/ucspi-tcp