Bump checkstyle from 8.43 to 9.0.1

Bumps [checkstyle](https://github.com/checkstyle/checkstyle) from 8.43 to 9.0.1.
- [Release notes](https://github.com/checkstyle/checkstyle/releases)
- [Commits](checkstyle/checkstyle@checkstyle-8.43...checkstyle-9.0.1)

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

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

build.gradle

@@ -45,7 +45,7 @@ dependencies {
     testImplementation("org.hamcrest:hamcrest:2.2")
     testImplementation("com.docu-tools:poipath:1.0.0")
 
-    checkstyle 'com.puppycrawl.tools:checkstyle:8.43'
+    checkstyle 'com.puppycrawl.tools:checkstyle:9.0.1'
 }
 
 tasks.withType(Checkstyle) {