community/webkit2gtk-4.1: new aport

Introduces the libsoup3 version of WebKit2GTK for GTK+3.

GNOME is currently trying to remove all libsoup2 dependencies for the 43 release, and that includes WebKit with libsoup2 support. One affected package is GNOME Boxes (see relevant mr), and judging by this, more have also been ported.

This doesn't change anything at the moment (affected packages would need to be rebuilt to use this version, plus a lot of these libsoup3 ports haven't yet landed in stable releases); I'm adding it now so that it doesn't cause any unnecessary slowdowns when GNOME 43 is released.

The aforementioned libsoup2 to libsoup3 migration doesn't affect GTK4 apps since webkit2gtk-5.0 requires libsoup3 by default.

cc @team/gnome

ref: https://gitlab.gnome.org/GNOME/libsoup/-/issues/218

(marking as draft to see if CI passes successfully)