Describe the bug

Distros currently need to build webkitgtk 3 times: once for GTK4 (6.0 API), once for GTK3 + libsoup3 (4.1 API ) and once for GTK3 + libsoup2.4 (4.0 API). Distros would like to drop the GTK3 + libsoup 2.4 build. The 4.0 and 4.1 APIs are the same except for the switch from libsoup 2.4 to libsoup 3.

Expected behavior
Please allow building font-manager with webkitgtk 4.1. I understand that it is already possible to build without the Google Fonts feature to build without webkitgtk 4.0.

I noticed that the wip-gtk4 branch has a commit f1d2454 to switch to the 6.0 API (which also uses libsoup3). Is it possible to port the libsoup3 work back to the stable branch of font-manager?