HDDS-13118. Remove duplicate mockito-core dependency from hdds-test-utils (#8508)

Author: chungen0126

hadoop-hdds/test-utils/pom.xml

@@ -57,11 +57,6 @@
       <artifactId>junit-platform-launcher</artifactId>
       <scope>provided</scope>
     </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>provided</scope>
-    </dependency>
     <dependency>
       <groupId>ch.qos.reload4j</groupId>
       <artifactId>reload4j</artifactId>