www/webkit2-gtk3: update to 2.34.0
PR: 255528
Changes: https://webkitgtk.org/2021/03/18/webkitgtk2.30.6-released.html
https://webkitgtk.org/2021/03/26/webkitgtk2.32.0-released.html https://webkitgtk.org/2021/05/10/webkitgtk2.32.1-released.html https://webkitgtk.org/2021/05/14/webkitgtk2.33.1-released.html https://webkitgtk.org/2021/06/08/webkitgtk2.33.2-released.html https://webkitgtk.org/2021/07/09/webkitgtk2.32.2-released.html https://webkitgtk.org/2021/07/23/webkitgtk2.32.3-released.html https://webkitgtk.org/2021/08/16/webkitgtk2.33.3-released.html https://webkitgtk.org/2021/09/17/webkitgtk2.32.4-released.html https://webkitgtk.org/2021/09/22/webkitgtk2.34.0-released.html