net/keycloak: Update 26.0.8 => 26.2.3

Changelogs:
https://www.keycloak.org/2025/01/keycloak-2610-released
https://www.keycloak.org/2025/02/keycloak-2611-released
https://www.keycloak.org/2025/02/keycloak-2612-released
https://www.keycloak.org/2025/02/keycloak-2613-released
https://www.keycloak.org/2025/03/keycloak-2614-released
https://www.keycloak.org/2025/04/keycloak-2615-released
https://www.keycloak.org/2025/04/keycloak-2620-released
https://www.keycloak.org/2025/04/keycloak-2621-released
https://www.keycloak.org/2025/04/keycloak-2622-released
https://www.keycloak.org/2025/05/keycloak-2623-released

PR: 286624
Security: CVE-2025-3910
Security: CVE-2025-3501
Security: CVE-2024-12397
Security: CVE-2025-0736
Security: CVE-2024-47072
Security: CVE-2025-0736
Security: CVE-2024-47072
Security: CVE-2021-44549
Security: CVE-2024-10973
Security: CVE-2024-10451
Security: CVE-2024-10270
Security: CVE-2024-10492
Security: CVE-2024-9666
Security: CVE-2024-10039
Security: CVE-2024-11736
Security: CVE-2024-11734
MFH: 2025Q2
(cherry picked from commit b2e669b11991d382d2d0f17a1f8262b74e3e8bb1)