net/shadowsocks-libev: Deprecate and set expiration date to 2024-11-30

Abandonware, no active development.
Upstream recommends migrating to net/shadowsocks-rust

Reference:
https://github.com/shadowsocks/shadowsocks-libev

PR: 282511
Reviewed by: Xiaoding Liu <xiaoding+freebsd@xiaoding.org> (maintainer)