Add property project.build.outputTimestamp for build reproducibility

Author: garydgregory

pom.xml

@@ -181,7 +181,8 @@
     <japicmp.skip>false</japicmp.skip>
 
     <commons.release.isDistModule>true</commons.release.isDistModule>
-  </properties>
+    <project.build.outputTimestamp>2024-01-01T00:00:00Z</project.build.outputTimestamp>
+</properties>
 
   <build>
     <defaultGoal>clean verify apache-rat:check japicmp:cmp spotbugs:check pmd:check pmd:cpd-check javadoc:javadoc checkstyle:check</defaultGoal>