[3.21] community/openjdk21: security upgrade to 21.0.6
(cherry picked from commit 0bf01c4e)
https://www.oracle.com/security-alerts/cpujan2025.html#AppendixJAVA
(cherry picked from commit 0bf01c4e)
https://www.oracle.com/security-alerts/cpujan2025.html#AppendixJAVA