www/squid: Update 6.12 => 6.13

Changelog:
https://github.com/squid-cache/squid/releases/tag/SQUID_6_13

• Move MASTER_SITES to github - upstream stopped publishing archives anywhere except github.
• Improve local patches for build NIS support.
• Rename patch-src-cf.data.pre to patch-src_cf.data.pre and refresh.

PR: 285493
Approved by: Pavel Timofeev <timp87@gmail.com> (maintainer)
Co-authored-by: Pavel Timofeev <timp87@gmail.com>
MFH: 2025Q2

(cherry picked from commit 941306d39fe47259c25f5b2b197d06bf6496dd12)