Bump de.undercouch.download from 5.5.0 to 5.6.0 (#1028)

Author: dependabot[bot]

build.gradle

@@ -6,7 +6,7 @@ plugins {
   id 'pmd' // code check, working on source code
   id 'com.diffplug.spotless' version '6.25.0' //code format
   id 'com.github.spotbugs' version '6.0.7' // code check, working on byte code
-  id 'de.undercouch.download' version '5.5.0'
+  id 'de.undercouch.download' version '5.6.0'
   id 'kr.motd.sphinx' version '2.10.1' // documentation generation
   id 'jacoco' // java code coverage plugin
   id "org.sonarqube" version "4.4.1.3373" // sonarqube