Fix wrong PT/TF categories in CI report
# What does this PR do?

Current `notification_service.py` has
```
if re.search("_tf_", line):
    model_results[model]["failed"]["TensorFlow"][artifact_path["gpu"]] += 1
```
which will put all `test_pt_tf_model_equivalence` under `TensorFlow` even it is from the PT (cross) tests, like
```
tests/models/albert/test_modeling_albert.py::AlbertModelTest::test_pt_tf_model_equivalence
```
This PR fixes this issue.
_The documentation is not available anymore as the PR was closed or merged._