tier2: test/jdk/tools/jpackage/junit/junit.java needs updating for jtreg 6

Sample error:
test/jdk/tools/jpackage/junit/jdk/jpackage/internal/PathGroupTest.java:37: error: package org.hamcrest does not exist
import static org.hamcrest.CoreMatchers.equalTo;
                          ^


This test is a wrapper around a shell script that invokes JUnit directly.
The `@library` needs to be updated to include the new hamcrest.jar file.