SONAR-13905 upgrade Hazelcast from 3.12.7 to 3.12.9

to mitigate the vulnerabilities brought by the bundled
jackson-core dependency.

The release notes of 3.12.8 and 3.12.9 highlights only bug-fixes:
https://docs.hazelcast.org/docs/rn/index.html#3-12-9

build.gradle

@@ -235,7 +235,7 @@ subprojects {
       dependency "com.google.protobuf:protobuf-java:${protobufVersion}"
       // Do not upgrade H2 to 1.4.200 because of instability: https://github.com/h2database/h2database/issues/2205
       dependency 'com.h2database:h2:1.4.199'
-      dependencySet(group: 'com.hazelcast', version: '3.12.7') {
+      dependencySet(group: 'com.hazelcast', version: '3.12.9') {
         entry 'hazelcast'
         entry 'hazelcast-client'
       }