Python: readded mocked HF unit test

[eavanvalkenburg]

Motivation and Context

We moved all Hugging Face tests to integration, because they connect to HF to download models, now readded tests with mocking, not yet for streaming.

Description

Contribution Checklist

• [x] The code builds clean without any errors or warnings
• [x] The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• [x] All unit tests pass, and I have added new tests where possible
• [x] I didn't break anyone :smile: