Add new contributors

Chie Taguchi [1] for:

security/masscan

Pavel Timofeev [2] for:

net/3proxy
www/squid
www/squid-devel
www/ufdbguard

David Kalliecharan [3] for:

devel/py-astor
devel/py-llvmlite
devel/py-numba
devel/py-rply
lang/py-hy

PR: 219886 [1]
PR: 220518 [2]
PR: 220709 [3]
Approved by: garga (mentor)
Differential Revision: https://reviews.freebsd.org/D11592