chore(deps): update dependency org.apache.maven.plugins:maven-checkstyle-plugin to v3

Author: renovatebot-confluentinc[bot]

pom.xml

@@ -350,7 +350,7 @@
                     <plugin>
                       <groupId>org.apache.maven.plugins</groupId>
                       <artifactId>maven-checkstyle-plugin</artifactId>
-                      <version>2.17</version>
+                      <version>3.6.0</version>
                     </plugin>
                     <plugin>
                         <groupId>com.github.spotbugs</groupId>