Bump checkstyle from 6.19 to 8.29

Bumps [checkstyle](https://github.com/checkstyle/checkstyle) from 6.19 to 8.29.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-6.19...checkstyle-8.29)

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

Author: dependabot[bot]

pom.xml

@@ -44,7 +44,7 @@
         <maven-compiler-plugin.version>3.8.0</maven-compiler-plugin.version>
         <maven-surefire-plugin.version>3.0.0-M1</maven-surefire-plugin.version>
         <os-maven-plugin.version>1.4.1.Final</os-maven-plugin.version>
-        <puppycrawl.checkstyle.version>6.19</puppycrawl.checkstyle.version>
+        <puppycrawl.checkstyle.version>8.29</puppycrawl.checkstyle.version>
         <spotbugs-maven-plugin.version>3.1.8</spotbugs-maven-plugin.version>
     </properties>