b601a610c5
Starting with Jenkins LTS 2.504.2 upstream uses JDK21 in published images. Let's follow upstream and run on a modern JDK. All FreeBSD architectures that have JDK17 also have JDK21. NB: Jobs in Jenkins can/should use their own compiler version. See also: https://www.jenkins.io/doc/book/platform-information/upgrade-java-to-21/index.html PR: 287112 Approved by: lwhsu@ (maintainer)