Update dependency checkstyle to v13

renovate[bot] · web-flow · commit 5558a1070b5b · 2026-01-31T17:53:04.000Z
diff --git a/build.gradle.kts b/build.gradle.kts
@@ -36,7 +36,7 @@ java {
 }
 
 checkstyle {
-    toolVersion = "12.3.0"
+    toolVersion = "13.1.0"
     maxWarnings = 0
 }
 
