Bump maven-checkstyle-plugin from 3.2.0 to 3.2.1 in /p3c-pmd

Bumps [maven-checkstyle-plugin](https://github.com/apache/maven-checkstyle-plugin) from 3.2.0 to 3.2.1.
- [Release notes](https://github.com/apache/maven-checkstyle-plugin/releases)
- [Commits](apache/maven-checkstyle-plugin@maven-checkstyle-plugin-3.2.0...maven-checkstyle-plugin-3.2.1)

---
updated-dependencies:
- dependency-name: org.apache.maven.plugins:maven-checkstyle-plugin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

p3c-pmd/pom.xml

@@ -53,7 +53,7 @@
         <!--enforce-->
         <enforce.activate>true</enforce.activate>
         <maven-enforcer-plugin.version>3.0.0-M3</maven-enforcer-plugin.version>
-        <checkstyle.plugin.version>3.2.0</checkstyle.plugin.version>
+        <checkstyle.plugin.version>3.2.1</checkstyle.plugin.version>
         <checkstyle.version>10.4</checkstyle.version>
         <checkstyle.configdir>src/site/resources/checkstyle
         </checkstyle.configdir>