libsoup: Workaround build error with GCC 14
Hi all,
This is the third of the preliminary MRs for !1501 (merged) -- @seungha.yang 's fix for libsoup.
Please note that this fix doesn't apply to current master -- they've removed SoupSocket in https://github.com/GNOME/libsoup/commit/9f357b2283f20c2f39c6095c56ec1747bc4561ad (2.99.3 onwards).