Test with Java 21.

Jenkinsfile

@@ -1,11 +1,11 @@
-#!groovy
-def recentLTS = '2.375.2'
+/*
+ See the documentation for more options:
+ https://github.com/jenkins-infra/pipeline-library/
+*/
 buildPlugin(
-  // Container agents start faster and are easier to administer
-  useContainerAgent: true,
-  configurations: [
-    [platform: 'linux',   jdk: '11'],
-    [platform: 'linux',   jdk: '17', jenkins: recentLTS],
-    [platform: 'windows', jdk: '17', jenkins: recentLTS],
-  ]
-)
+        forkCount: '1C', // run this number of tests in parallel for faster feedback.  If the number terminates with a 'C', the value will be multiplied by the number of available CPU cores
+        useContainerAgent: true, // Set to `false` if you need to use Docker for containerized tests
+        configurations: [
+                [platform: 'linux', jdk: 21],
+                [platform: 'windows', jdk: 17],
+        ])