devel/gcli: update to 2.6.1

A patch release, fixing some more issues with liblowdown 1.4.0.

Changelog: https://lists.sr.ht/~herrhotzenplotz/gcli-announce/%3C22C4Q2273YPES.29HJ1NHLN3T4P@triton.lab.herrhotzenplotz.de%3E

MFH: 2025Q1