Fix Gtksourceview3 detection with new opam package
lablgtk3-sourceview3 seems the new name of the ocamlfind package lablgtk3.sourceview3
Edited by François Bobot
GitLab upgrade completed. Current version is 18.8.7
https://about.gitlab.com/releases/2026/01/15/gitlab-18-8-released/
lablgtk3-sourceview3 seems the new name of the ocamlfind package lablgtk3.sourceview3