client: Support WebKit 4.1 API
client: Support WebKit 4.1 API

Fedora 37 dropped webkit2gtk3 from their default desktop installation,
and only ships with webkit2gtk4.1 now. Confusingly, this is *not* GTK4,
but the GTK3 binding linked against libsoup 3.

Also drop the unnecessary NOQA marker for the require_version() call.

martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit