dependencies: Upgrade mockito 3.5 to 4.5 (#2316)

* refactor: move tests of leader-followers into correct package

* dep: remove version constraint for Mockito in acyclic-visitor

* dep: remove version constraint for Mockito in caching

* chore: cleanup mockito-core import on some POMs

* dep: upgrade core.mocktio 3.5.6 to 4.5.1

"- org.mockito.Mockito#verifyZeroInteractions an alias of verifyNoMoreInteractions"
https://github.com/mockito/mockito/commit/caf35b24e2764df0498469526ecb3e7ec68a0430

event-aggregator/src/test/java/com/iluwatar/event/aggregator/EventEmitterTest.java

@@ -24,16 +24,14 @@
  */
 package com.iluwatar.event.aggregator;
 
-import static org.mockito.Matchers.eq;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.Mockito.verifyZeroInteractions;
 
 import java.util.Objects;
 import java.util.function.BiFunction;
-import java.util.function.Function;
 import java.util.function.Supplier;
 import org.junit.jupiter.api.Test;
 
@@ -111,7 +109,7 @@ abstract class EventEmitterTest<E extends EventEmitter> {
         }
       } else {
         // On any other normal day, the observers should have received nothing at all
-        verifyZeroInteractions(observers);
+        verifyNoMoreInteractions(observers);
       }
     }
 

event-aggregator/src/test/java/com/iluwatar/event/aggregator/KingsHandTest.java

@@ -24,12 +24,11 @@
  */
 package com.iluwatar.event.aggregator;
 
-import static org.mockito.Matchers.eq;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.Mockito.verifyZeroInteractions;
 
 import java.util.Arrays;
 import org.junit.jupiter.api.Test;
@@ -63,7 +62,7 @@ class KingsHandTest extends EventEmitterTest<KingsHand> {
     kingsHand.registerObserver(observer, Event.WHITE_WALKERS_SIGHTED);
 
     // The kings hand should not pass any events before he received one
-    verifyZeroInteractions(observer);
+    verifyNoMoreInteractions(observer);
 
     // Verify if each event is passed on to the observer, nothing less, nothing more.
     Arrays.stream(Event.values()).forEach(event -> {