Use pmd 6.23.0 for checks

Author: adangel

pom.xml

@@ -71,8 +71,8 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
 
-        <pmd.build-tools.version>6-SNAPSHOT</pmd.build-tools.version>
-        <pmd.check.version>6.21.0</pmd.check.version>
+        <pmd.build-tools.version>6</pmd.build-tools.version>
+        <pmd.check.version>6.23.0</pmd.check.version>
 
         <jflex-output>${project.build.directory}/generated-sources/jflex</jflex-output>