CVE-2026-10636 Use-after-free in Zephyr IPv4 IGMP send path (`igmp_send`)

In Zephyr's IPv4 IGMP implementation, igmpsend in subsys/net/ip/igmp.c read the network interface back out of the packet via netpktifacepkt after the packet had been handed to netsenddata. On the successful-send path the packet's last reference may already have been released by the L2 driver or b...