CVE-2026-10634 Use-after-free in Zephyr native TCP `net_tcp_foreach()` due to dropping `tcp_lock` during the callback

Zephyr's native TCP stack iterates the global connection list in nettcpforeach subsys/net/ip/tcp.c using the SYSSLISTFOREACHCONTAINERSAFE macro, which caches a pointer to the next list node. Prior to this fix the function released tcplock while invoking the per-connection callback and re-acquired...