CVE-2026-10640 Use-after-free reading `net_pkt` `iface` after send in IPv6 Neighbor Discovery (`ipv6_nbr.c`)

Zephyr's IPv6 Neighbor Discovery send paths netipv6sendna, netipv6sendns, netipv6sendrs in subsys/net/ip/ipv6nbr.c updated the per-interface ICMP-sent statistics by calling netpktifacepkt after netsenddatapkt had already returned successfully. On the success path the network stack owns and releas...