SLING-8706: update mockito, fix unit tests (#36)

diff --git a/pom.xml b/pom.xml
index 0bda7fe..2dc28d7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -192,7 +192,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>4.1.0</version>
+            <version>4.4.0</version>
             <scope>test</scope>
         </dependency>
         <dependency>
diff --git a/src/test/java/org/apache/sling/models/impl/OptionalObjectsTest.java b/src/test/java/org/apache/sling/models/impl/OptionalObjectsTest.java
index 6fd0bfb..250714d 100644
--- a/src/test/java/org/apache/sling/models/impl/OptionalObjectsTest.java
+++ b/src/test/java/org/apache/sling/models/impl/OptionalObjectsTest.java
@@ -34,14 +34,14 @@
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.Mockito;
-import org.mockito.runners.MockitoJUnitRunner;
+import org.mockito.junit.MockitoJUnitRunner;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.Constants;
 import org.osgi.framework.InvalidSyntaxException;
 import org.osgi.framework.ServiceReference;
 import org.slf4j.Logger;
 import static org.junit.Assert.*;
-import static org.mockito.Matchers.eq;
+import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;