Unit Test: Add error handling for rate limit exceeded in model list

[HeyangQin]

This PR fixes the random failure in our unit test due to HTTP 429

[adk9]

Thanks for the fix. I think this will definitely make test_inference less flaky.

I've two high-level concerns though about what's happening here:

1. What's the reason for the default model cache time to be 1 day? The models/tasks we're testing barely update so we could perhaps set a much longer cache time?
2. We get rate-limited because we're making ~750k requests (getting model information for all models on HF) to test only 24 models. I think a better approach is to pass a filter to api.list_models() to get information of only the models we're interested in testing?

[loadams]

Thanks for the fix. I think this will definitely make test_inference less flaky.

I've two high-level concerns though about what's happening here:

1. What's the reason for the default model cache time to be 1 day? The models/tasks we're testing barely update so we could perhaps set a much longer cache time?
2. We get rate-limited because we're making ~750k requests (getting model information for all models on HF) to test only 24 models. I think a better approach is to pass a filter to api.list_models() to get information of only the models we're interested in testing?

It was re-set here, though we had it set to 1 day before this: https://github.com/microsoft/DeepSpeed/pull/5688/files