GitLab

* [QA] Add error handling

-Standardize test failure handling using the unified 'test_fail' function and 'error_exit' function.
Signed-off-by: Linxi Ding <linxid@nvidia.com>

* Update script to use explicit python3, pip3, and python3 -m pytest calls

- Change pip to pip3.
- Change python to python3.
- Change pytest to python3 -m pytest.
Signed-off-by: Linxi Ding <linxid@nvidia.com>

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Signed-off-by: Linxi Ding <linxid@nvidia.com>