Bump checkstyle from 8.18 to 8.29

Bumps [checkstyle](https://github.com/checkstyle/checkstyle) from 8.18 to 8.29.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-8.18...checkstyle-8.29)

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

pom.xml

@@ -130,7 +130,7 @@
             overridden by a CI job of the Checkstyle project so that they can
             check for regressions. Which is obviously good for us, too.
          -->
-        <puppycrawl.checkstyle.version>8.18</puppycrawl.checkstyle.version>
+        <puppycrawl.checkstyle.version>8.29</puppycrawl.checkstyle.version>
 
         <!-- Build settings -->