Bump com.puppycrawl.tools:checkstyle from 10.20.2 to 10.21.0

Bumps [com.puppycrawl.tools:checkstyle](https://github.com/checkstyle/checkstyle) from 10.20.2 to 10.21.0.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-10.20.2...checkstyle-10.21.0)

---
updated-dependencies:
- dependency-name: com.puppycrawl.tools:checkstyle
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

pom.xml

@@ -23,7 +23,7 @@
         <formatter-maven-plugin.version>2.23.0</formatter-maven-plugin.version>
         <impsort-maven-plugin.version>1.6.2</impsort-maven-plugin.version>
         <xml-format-maven-plugin.version>4.0.1</xml-format-maven-plugin.version>
-        <checkstyle.version>10.20.2</checkstyle.version>
+        <checkstyle.version>10.21.0</checkstyle.version>
         <profile.id>jvm</profile.id>
         <!-- Default values for format -->
         <src.format.goal>format</src.format.goal>