Integrate he following FRR security fixes to Sagitta and Circinus:
Sagitta/Circinus:
https://github.com/FRRouting/frr/pull/19983 (CVE-2025-61099 through CVE-2025-61107)
Circinus:
https://github.com/FRRouting/frr/pull/21098 (CVE-2026-37460)
https://github.com/FRRouting/frr/pull/21074 (CVE-2026-37459)
https://github.com/FRRouting/frr/pull/21054 (CVE-2026-37457)