Update dependency checkstyle to v13

renovate[bot] · web-flow · commit 334660605509 · 2026-04-02T07:04:10.000Z
diff --git a/build.gradle b/build.gradle
@@ -219,7 +219,7 @@ pmd {
 }
 
 checkstyle {
-  toolVersion = "12.3.1"
+  toolVersion = "13.4.0"
 }
 
 jacoco {
