Bump Lombok version to allow building with a JDK12>=12 (apache#5772) (a…

…pache#5773)

Fixes apache#5772 

### Motivation

I would like to be able to build Pulsar with at least JDK12.

### Modifications

Bumping lombok dep.

### Verifying this change


This change is a trivial rework / code cleanup without any test coverage.

pom.xml

@@ -1056,7 +1056,7 @@ flexible messaging model and an intuitive client API.</description>
       <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
-        <version>1.18.4</version>
+        <version>1.18.10</version>
       </dependency>
 
       <dependency>