sysutils/bareos18-*: Mark DEPRECATED

- Bareos only supports last 3 major releases at any points and current
  supported release are 20.X, 21.X and 22.X. See for more information:
- Set EXPIRATION_DATE 2023-06-01

Approved by:	portmgr (blanket)

sysutils/bareos18-server/Makefile

@@ -13,6 +13,9 @@ WWW=		https://www.bareos.org/
 LICENSE=	AGPLv3 LGPL3
 LICENSE_COMB=	multi
 
+DEPRECATED=	Upstream EOL reached on 2020-02-03
+EXPIRATION_DATE=	2023-06-01
+
 CONFLICTS?=	bareos17-server bareos16-server bareos-server
 
 LIB_DEPENDS+=	liblzo2.so:archivers/lzo2 \