Support JDK 21.

See #1425

Jenkinsfile

@@ -39,10 +39,10 @@ pipeline {
 						}
 					}
 				}
-				stage('Publish JDK 20 + Cassandra 3.11') {
+				stage('Publish JDK 21 + Cassandra 3.11') {
 					when {
 						anyOf {
-							changeset "ci/openjdk20-8-cassandra-3.11/**"
+							changeset "ci/openjdk21-8-cassandra-3.11/**"
 							changeset "ci/pipeline.properties"
 						}
 					}
@@ -51,7 +51,7 @@ pipeline {
 
 					steps {
 						script {
-							def image = docker.build("springci/spring-data-with-cassandra-3.11:${p['java.next.tag']}", "--build-arg BASE=${p['docker.java.next.image']} --build-arg CASSANDRA=${p['docker.cassandra.3.version']} ci/openjdk20-8-cassandra-3.11/")
+							def image = docker.build("springci/spring-data-with-cassandra-3.11:${p['java.next.tag']}", "--build-arg BASE=${p['docker.java.next.image']} --build-arg CASSANDRA=${p['docker.cassandra.3.version']} ci/openjdk21-8-cassandra-3.11/")
 							docker.withRegistry(p['docker.registry'], p['docker.credentials']) {
 								image.push()
 							}

pom.xml

@@ -152,6 +152,12 @@
 				<artifactId>assertj-core</artifactId>
 				<version>${assertj}</version>
 				<scope>test</scope>
+				<exclusions>
+					<exclusion>
+						<groupId>net.bytebuddy</groupId>
+						<artifactId>byte-buddy</artifactId>
+					</exclusion>
+				</exclusions>
 			</dependency>
 
 			<dependency>