Upgrade Hazelcast to 3.12.11

Closes gh-1767

Author: eleftherias

gradle/dependency-management.gradle

@@ -9,7 +9,7 @@ dependencyManagement {
 	}
 
 	dependencies {
-		dependencySet(group: 'com.hazelcast', version: '3.12.7') {
+		dependencySet(group: 'com.hazelcast', version: '3.12.11') {
 			entry 'hazelcast'
 			entry 'hazelcast-client'
 		}

spring-session-hazelcast/src/integration-test/java/org/springframework/session/hazelcast/ClientServerHazelcastIndexedSessionRepositoryITests.java

@@ -46,7 +46,7 @@
 @WebAppConfiguration
 class ClientServerHazelcastIndexedSessionRepositoryITests extends AbstractHazelcastIndexedSessionRepositoryITests {
 
-	private static GenericContainer container = new GenericContainer<>("hazelcast/hazelcast:3.12.3")
+	private static GenericContainer container = new GenericContainer<>("hazelcast/hazelcast:3.12.11")
 			.withExposedPorts(5701).withCopyFileToContainer(MountableFile.forClasspathResource("/hazelcast-server.xml"),
 					"/opt/hazelcast/hazelcast.xml");