Update CI properties.

See #1592

ci/pipeline.properties

@@ -1,10 +1,10 @@
 # Java versions
 java.main.tag=17.0.8_7-jdk-focal
-java.next.tag=20-jdk-jammy
+java.next.tag=21-jdk-bullseye
 
 # Docker container images - standard
 docker.java.main.image=harbor-repo.vmware.com/dockerhub-proxy-cache/library/eclipse-temurin:${java.main.tag}
-docker.java.next.image=harbor-repo.vmware.com/dockerhub-proxy-cache/library/eclipse-temurin:${java.next.tag}
+docker.java.next.image=harbor-repo.vmware.com/dockerhub-proxy-cache/library/openjdk:${java.next.tag}
 
 # Supported versions of MongoDB
 docker.mongodb.4.4.version=4.4.23