Simplify build pipeline.

See #1537

Author: mp911de

Jenkinsfile

@@ -13,12 +13,6 @@ pipeline {
 
 	stages {
 		stage("test: baseline (Java 17)") {
-			when {
-				anyOf {
-					branch 'main'
-					not { triggeredBy 'UpstreamCause' }
-				}
-			}
 			agent {
 				label 'data'
 			}
@@ -29,7 +23,7 @@ pipeline {
 			steps {
 				script {
 					docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-						docker.image('openjdk:17').inside('-v $HOME:/tmp/jenkins-home') {
+						docker.image('openjdk:17-bullseye').inside('-v $HOME:/tmp/jenkins-home') {
 							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml clean dependency:list verify -Dsort -B'
 						}
 					}
@@ -38,12 +32,6 @@ pipeline {
 		}
 
 		stage('Build project and release to artifactory') {
-			when {
-				anyOf {
-					branch 'main'
-					not { triggeredBy 'UpstreamCause' }
-				}
-			}
 			agent {
 				label 'data'
 			}
@@ -56,7 +44,7 @@ pipeline {
 			steps {
 				script {
 					docker.withRegistry('', 'hub.docker.com-springbuildmaster') {
-						docker.image('openjdk:17').inside('-v $HOME:/tmp/jenkins-home') {
+						docker.image('openjdk:17-bullseye').inside('-v $HOME:/tmp/jenkins-home') {
 							sh 'MAVEN_OPTS="-Duser.name=jenkins -Duser.home=/tmp/jenkins-home" ./mvnw -s settings.xml -Pci,artifactory ' +
 									'-Dartifactory.server=https://repo.spring.io ' +
 									"-Dartifactory.username=${ARTIFACTORY_USR} " +