[KEYCLOAK-6518] Added explicit guava dependency instead of relying on transitive dependency.

testsuite/integration-arquillian/tests/base/pom.xml

@@ -115,6 +115,10 @@
             <version>1.2.1</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+        </dependency>
     </dependencies>
     
     <build>