Update dependency checkstyle to v10.20.2 (#171)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

build.gradle

@@ -113,7 +113,7 @@ task smoke(type: Test) {
 
 checkstyle {
   maxWarnings = 0
-  toolVersion = '10.20.1'
+  toolVersion = '10.20.2'
   getConfigDirectory().set(new File(rootDir, 'config/checkstyle'))
 }