remove simple to fix warnings

Co-authored-by: Christoph <tobi@urpost.de>

src/main/java/mops/gruppen2/service/APIFormatterService.java

@@ -7,7 +7,9 @@ import org.springframework.stereotype.Service;
 import java.util.List;
 
 @Service
-public class APIFormatterService {
+public final class APIFormatterService {
+
+    private APIFormatterService() {}
 
     public static GroupRequestWrapper wrap(Long status, List<Group> groupList) {
         return new GroupRequestWrapper(status, groupList);