Bump maven-checkstyle-plugin from 2.15 to 3.1.1

Bumps [maven-checkstyle-plugin](https://github.com/apache/maven-checkstyle-plugin) from 2.15 to 3.1.1.
- [Release notes](https://github.com/apache/maven-checkstyle-plugin/releases)
- [Commits](apache/maven-checkstyle-plugin@maven-checkstyle-plugin-2.15...maven-checkstyle-plugin-3.1.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

pom.xml

@@ -237,7 +237,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-checkstyle-plugin</artifactId>
-        <version>2.15</version>
+        <version>3.1.1</version>
         <configuration>
           <consoleOutput>true</consoleOutput>
           <configLocation>src/etc/checkstyle.xml</configLocation>