textproc/libxslt: Update to 1.1.35 and migrate to CMake

Changelog: https://gitlab.gnome.org/GNOME/libxslt/-/releases#v1.1.35

I'd like to thank both tcberner and mandree for reviewing,
suggesting improvements and helping out in general. I'd also like
thank antoine for doing exp-runs.

PR: 262288
Reviewed by: tcberner, mandree
Approved by: desktop (tcberner)
Differential Revision: https://reviews.freebsd.org/D34384
Exp-run by: antoine