java/jad: Mark DEPRECATED

This is a version that is over 25 years old and has multiple vulnerabilities.

https://www.cve.org/CVERecord?id=CVE-2016-20049
https://www.cve.org/CVERecord?id=CVE-2017-20227

PR: 295464
Approved by: ale (maintainer)
Approved by: fluffy (mentor)