textproc/libxslt: update to 1.1.43

Changelog: https://gitlab.gnome.org/GNOME/libxslt/-/blob/v1.1.43/NEWS

Fixes CVE-2024-55549 and CVE-2025-24855

Upstream have disabled CRYPTO and (new OPTION) PLUGINS by default,
as they will be removed in a future version, but the port continues
to have them enabled by default until at least the next update.

Reported by: ngie
Security: a96cd659-303e-11f0-94b5-54ee755069b5
PR: 286782

(cherry picked from commit 11d181b834f29d60d8ce03734eed1bf1eab35072)