dns/bind920: update to 9.20.23
Changes: https://downloads.isc.org/isc/bind9/9.20.23/doc/arm/html/notes.html#notes-for-bind-9-20-23
Security: CVE-2026-3592, CVE-2026-3039, CVE-2026-5946,
CVE-2026-5950, CVE-2026-5947, CVE-2026-3593
(cherry picked from commit 074766706898a05719a5132d2f64ffbd7ff06fdc)