Unbound is vulnerable to CVE-2025-5994: "Cache poisoning via the ECS-enabled
Rebirthday Attack" if built with --enable-subnet, which is not the case in
Buildroot, so mark it as not applicable.
https://nlnetlabs.nl/downloads/unbound/CVE-2025-5994.txt
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
(cherry picked from commit c7721b0174)
Signed-off-by: Titouan Christophe <titouan.christophe@mind.be>