CVE-2026-14366 SiWx91x WiFi driver double-unref / use-after-free of caller-owned TX net_pkt

The Silicon Labs SiWx917 WiFi driver's transmit callback siwx91xsend in drivers/wifi/siwx91x/siwx91xwifi.c frees a network packet it does not own. In the Zephyr TX path the netpkt is owned by the L2/networking stack; the driver only borrows it to copy the frame bytes into a local netbuf. Before t...