chore: fix the wrong directory path in release infra

PiperOrigin-RevId: 660967513

Author: yinghsienwu

.kokoro/release.sh

@@ -30,7 +30,7 @@ twine upload --username __token__ --password "${GCA_TWINE_PASSWORD}" dist/*
 
 # Move into the `vertexai` package, build the distribution and upload.
 VERTEXAI_TWINE_PASSWORD=$(cat "${KOKORO_KEYSTORE_DIR}/73713_vertexai-pypi-token-1")
-cd github/python-aiplatform/pypi/_vertex_ai_placeholder
+cd pypi/_vertex_ai_placeholder
 python3 -m build
 twine upload --username __token__ --password "${VERTEXAI_TWINE_PASSWORD}" dist/*