Bug#1104054: libsoup2.4: CVE-2025-46421

[Jeremy Bícha]

Sean,

Ubuntu has pushed their update for CVE-2025-46421. It matches your WIP
patch except that Ubuntu didn't include the test changes.

https://launchpad.net/ubuntu/+source/libsoup2.4/2.74.3-10.1ubuntu1

Thank you,
Jeremy Bícha