Switch to libsoup3
GNOME is switching its core set from libsoup2 to libsoup3 for the GNOME 43 release. lollypop should switch too, but I don't think this is required in time for the GNOME 43 release since distros will need to keep libsoup2 around for a while longer
https://libsoup.org/libsoup-3.0/migrating-from-libsoup-2.html