open/test/jdk//java/foreign/TestMatrix.java is marked a manual test, one scenario is not, which is incongruent with the other test scenarios. This is not being run at all. update to manual so that the full test is run manually

add manual tag as per other tests

/* @test id=UpcallHighArity-FF
 * @modules java.base/jdk.internal.foreign
 * @build NativeTestHelper CallGeneratorHelper TestUpcallHighArity
 *
 * @run testng/othervm/native/manual
 * --enable-native-access=ALL-UNNAMED
 * -Djdk.internal.foreign.DowncallLinker.USE_SPEC=false
 * -Djdk.internal.foreign.UpcallLinker.USE_SPEC=false
 * TestUpcallHighArity
 */