Upgrade to Hazelcast 3.12.7

Closes gh-21333

Author: snicoll

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -70,7 +70,7 @@
 		<gson.version>2.8.6</gson.version>
 		<h2.version>1.4.200</h2.version>
 		<hamcrest.version>2.1</hamcrest.version>
-		<hazelcast.version>3.12.6</hazelcast.version>
+		<hazelcast.version>3.12.7</hazelcast.version>
 		<hazelcast-hibernate5.version>1.3.2</hazelcast-hibernate5.version>
 		<hibernate.version>5.4.14.Final</hibernate.version>
 		<hibernate-validator.version>6.0.19.Final</hibernate-validator.version>