Remove dependency on webkit2gtk
https://github.com/cvfosammmm/Setzer/issues/367
- webkit2gtk use was removed in https://github.com/cvfosammmm/Setzer/commit/1bd70d9153f4f6f43394924ec4536f4f24a2307a
- webkitgtk-6.0 use was added in https://github.com/cvfosammmm/Setzer/commit/4be303c997ed27ae86abbb61f913bf3a2a1081ee