[TEST] exclude org.elasticsearch.test.test package from test-jar

The package was only excluded during test-jar sources generation but ended up in the actual jar.

pom.xml

@@ -1288,6 +1288,8 @@
                             <excludes>
                                 <!-- unit tests for yaml suite parser & rest spec parser need to be excluded -->
                                 <exclude>org/elasticsearch/test/rest/test/**/*</exclude>
+                                <!-- unit tests for test framework classes-->
+                                <exclude>org/elasticsearch/test/test/**/*</exclude>
                             </excludes>
                         </configuration>
                     </execution>