refactor: remove code smell java:S5786 (#2159)

https://sonarcloud.io/organizations/iluwatar/rules?open=java%3AS5786&rule_key=java%3AS5786

monostate/src/test/java/com/iluwatar/monostate/LoadBalancerTest.java

@@ -41,7 +41,7 @@ import org.junit.jupiter.api.Test;
  *
  * @author Jeroen Meulemeester
  */
-public class LoadBalancerTest {
+class LoadBalancerTest {
 
   @Test
   void testSameStateAmongstAllInstances() {