Do not build against javadoc.io

Service is unstable right now and is not an official source.

Author: bclozel

build.gradle

@@ -18,7 +18,6 @@ subprojects {
 
 	ext.javadocLinks = [
 			"https://docs.oracle.com/en/java/javase/17/docs/api/",
-			"https://javadoc.io/doc/com.graphql-java/graphql-java/${graphQlJavaVersion}/",
 			"https://docs.spring.io/spring-framework/docs/${springFrameworkVersion}/javadoc-api/"
 	] as String[]