Bump com.puppycrawl.tools:checkstyle from 10.20.2 to 10.21.2

Bumps [com.puppycrawl.tools:checkstyle](https://github.com/checkstyle/checkstyle) from 10.20.2 to 10.21.2.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-10.20.2...checkstyle-10.21.2)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

pom.xml

@@ -48,7 +48,7 @@
     <junit.version>5.11.0</junit.version>
     <maven-enforcer-plugin.version>3.5.0</maven-enforcer-plugin.version>
     <maven-checkstyle-plugin.version>3.6.0</maven-checkstyle-plugin.version>
-    <checkstyle.version>10.20.2</checkstyle.version>
+    <checkstyle.version>10.21.2</checkstyle.version>
     <maven-surefire-plugin.version>3.5.2</maven-surefire-plugin.version>
     <jacoco-maven-plugin.version>0.8.4</jacoco-maven-plugin.version>
     <maven-javadoc-plugin.version>3.11.2</maven-javadoc-plugin.version>