Upgrade maven-checkstyle-plugin 3.5.0 -> 3.6.0 (#1377)

See:
- https://issues.apache.org/jira/issues/?jql=project%20%3D%20MCHECKSTYLE%20AND%20fixVersion%20%3E%203.5.0%20AND%20fixVersion%20%3C%3D%203.6.0
- apache/maven-checkstyle-plugin@maven-checkstyle-plugin-3.5.0...maven-checkstyle-plugin-3.6.0

pom.xml

@@ -672,7 +672,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-checkstyle-plugin</artifactId>
-                    <version>3.5.0</version>
+                    <version>3.6.0</version>
                     <configuration>
                         <checkstyleRules>
                             <!-- We only enable rules that are not enforced by