add a script to get time info. from GA workflow jobs
# What does this PR do?

As we might need to get the running time for workflow jobs again in the future, here is a simple script. It's probably better to move to the directory `utils`. I put it under `.github/scripts/` to emphasize this is really for GitHub Actions only.

The output looks like

```bash
(py39) λ python get_github_job_time.py --workflow_run_id 2945609517
Model tests (onnx, multi-gpu): 337
Model tests (onnx, single-gpu): 334
Torch CUDA extension tests (multi-gpu): 44
Torch CUDA extension tests (single-gpu): 43
TensorFlow pipelines (multi-gpu): 20
TensorFlow pipelines (single-gpu): 19
...
```

P.S. I will add another simple script to get test failures and their counts in another PR.
_The documentation is not available anymore as the PR was closed or merged._<|||||>Yes, I will move it to `utils`.