Use pypi packages from transformers and sagemaker extension

[tkilias]

Background

• we can't release the notebook-connector to pypi, because it depends on sagemaker and transformers-extension which are not released on pypi yet, for that reason, we specified them as git dependency
• However, python package with git dependencies or dependencies not available on pypi can't be released to pypi

Acceptance Criteria

• Replace git dependency with pypi versions