www/squid: Update 7.3 => 7.4

Changelog:
https://github.com/squid-cache/squid/releases/tag/SQUID_7_4

• Rework GSSAPI option a bit to make them more reliable.
• Update files/patch-configure to follow upstream changes.
• Split post-install - create post-install-*-on.

PR: 292732