Bump minimum requirements to match GTK4
Review Request #1138 — Created Nov. 21, 2021 and submitted
While technically, libpurple doesn't need to match Pidgin, we probably aren't going to bother with the differences right now. Since Pidgin is moving to GTK4, we don't need to require secondary dependencies that are older than what GTK4 needs.
bump or remove the version from here. Remove is probably preferred.