Use revision to download pretrained weights (grounded.py)

[AlexanderBarabanov]

Within this task, please add revision parameter and pin it to a specific commit for reproducibility and security purposes for from_pretrained() invocation in grounded.py

Please see an example in this PR #493

[mpryahin]

Thanks @AlexanderBarabanov! @eugene123tw is currently working on the model registry in his PR, this will cover all supported models

https://github.com/eugene123tw/geti-prompt/blob/6fe0282751424b55a2f7dce5f08ab59786fda772/library/src/getiprompt/registry.py#L68