Stay compatible with Java 8

Author: wmdietl

build.gradle

@@ -13,7 +13,7 @@ buildscript {
 
 plugins {
     // https://plugins.gradle.org/plugin/com.gradleup.shadow
-    id 'com.gradleup.shadow' version '8.3.6'
+    id 'com.gradleup.shadow' version '8.3.1'
     // https://plugins.gradle.org/plugin/de.undercouch.download
     id 'de.undercouch.download' version '5.6.0'
     id 'java'