title: Old version of checkstyle detected. Consider updating to >= v8.30
body: <p>Small question regarding a SonarQube + Checkstyle warning please.</p>
  <p>Currently, in my app, in my pom, I use the following Checkstyle plugin:</p>
  <pre><code>          &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-checkstyle-plugin&lt;/artifactId&gt;
                  &lt;version&gt;3.1.2&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;outputFile&gt;.out/reports/checkstyle/checkstyle-result.xml&lt;/outputFile&gt;
                      &lt;outputDirectory&gt;target/reports/checkstyle&lt;/outputDirectory&gt;
                      &lt;outputFileFormat&gt;xml&lt;/outputFileFormat&gt;
                  &lt;/configuration&gt;
              &lt;/plugin&gt;
  </code></pre>
  <p>This plugin is doing its job, no worries there.</p>
  <p>When I run SonarQube though, I get this warning</p>
  <pre><code>Old version of checkstyle detected. Consider updating to &gt;= v8.30
  For more information see: https://maven.apache.org/plugins/maven-checkstyle-plugin/examples/upgrading-checkstyle.html
  </code></pre>
  <p>I obviously went to read the website, but I am still having hard time understanding.</p>
  <p>The Checkstyle plugin I have is the latest known, version 3.1.2, checked on Maven central etc.</p>
  <p>In SonarQube, I am running on the latest version, 8.9 LTS, with the latest version of Checkstyle plugin as well.</p>
  <p>What am I missing please? Am I using some kind of wrong plugin?</p>