fix: add junit-vintage dep to avoid skipping post-compilation native tests

[mpeddada1]

In a test run conducted with java-pubsub, we see that after the native image generation phase, we end up with 0 tests being executed:

Finished generating 'native-tests' in 57.7s.
[INFO] Executing: /usr/local/google/home/mpeddada/IdeaProjects/native-image-experiments/graalvm23-update-submodule/java-pubsub/google-cloud-pubsub/target/native-tests --xml-output-dir /usr/local/google/home/mpeddada/IdeaProjects/native-image-experiments/graalvm23-update-submodule/java-pubsub/google-cloud-pubsub/target/native-test-reports -Djunit.platform.listeners.uid.tracking.output.dir=/usr/local/google/home/mpeddada/IdeaProjects/native-image-experiments/graalvm23-update-submodule/java-pubsub/google-cloud-pubsub/target/test-ids
JUnit Platform on Native Image - report
----------------------------------------
 
 
Test run finished after 3 ms
[         1 containers found      ]
[         0 containers skipped    ]
[         1 containers started    ]
[         0 containers aborted    ]
[         1 containers successful ]
[         0 containers failed     ]
[         0 tests found           ]
[         0 tests skipped         ]
[         0 tests started         ]
[         0 tests aborted         ]
[         0 tests successful      ]
[         0 tests failed          ]

Reproducer: https://github.com/mpeddada1/graalvm23-skipped-tests

As demonstrated in the reproducer, the junit-vintage-engine dependency is needed to be added to resolve this issue.

TODO:

• Modify the downstream test to use monorepo instead of the old org-policy repo.