textproc/diffutils: Update 3.8 => 3.11
Release announcement and changelog:
https://lists.gnu.org/archive/html/info-gnu/2025-02/msg00003.html
Improve port:
- replace PORTVERSION with DISTVERSION,
- remove unnecessary dependency from devel/libsigsegv,
- remove GNU_CONFIGURE_MANPREFIX,
- pet portclippy.
PR: 284552
Approved by: schaiba@gmail.com (maintainer)