Fix test_finetuning for env without cuda

[mreso]

What does this PR do?

This PR fixed test_finetuning.py for cpu only envs

Feature/Issue validation/testing

• Test A

$ nvidia-smi
NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.
$ python -m pytest tests/
============================================================================================================ test session starts =============================================================================================================
platform linux -- Python 3.10.13, pytest-7.4.3, pluggy-1.3.0
rootdir: /home/ubuntu/llama-recipes
configfile: pyproject.toml
plugins: mock-3.12.0
collected 22 items

tests/test_batching.py ss                                                                                                                                                                                                              [  9%]
tests/test_finetuning.py .....                                                                                                                                                                                                         [ 31%]
tests/test_sampler.py ..........                                                                                                                                                                                                       [ 77%]
tests/test_train_utils.py .                                                                                                                                                                                                            [ 81%]
tests/datasets/test_custom_dataset.py s.                                                                                                                                                                                               [ 90%]
tests/datasets/test_grammar_datasets.py s                                                                                                                                                                                              [ 95%]
tests/datasets/test_samsum_datasets.py s                                                                                                                                                                                               [100%]

============================================================================================================== warnings summary ==============================================================================================================
tests/conftest.py:45
  /home/ubuntu/llama-recipes/tests/conftest.py:45: PytestRemovedIn8Warning: The pytest_cmdline_preparse hook is deprecated and will be removed in a future release.
  Please use pytest_load_initial_conftests hook instead.
    @pytest.hookimpl(tryfirst=True)

src/llama_recipes/finetuning.py:5
  /home/ubuntu/llama-recipes/src/llama_recipes/finetuning.py:5: DeprecationWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html
    from pkg_resources import packaging

../miniconda3/envs/llama-recipes/lib/python3.10/site-packages/torch/cuda/__init__.py:611
  /home/ubuntu/miniconda3/envs/llama-recipes/lib/python3.10/site-packages/torch/cuda/__init__.py:611: UserWarning: Can't initialize NVML
    warnings.warn("Can't initialize NVML")

../miniconda3/envs/llama-recipes/lib/python3.10/site-packages/torch/distributed/_shard/checkpoint/__init__.py:8
  /home/ubuntu/miniconda3/envs/llama-recipes/lib/python3.10/site-packages/torch/distributed/_shard/checkpoint/__init__.py:8: DeprecationWarning: torch.distributed._shard.checkpoint will be deprecated, use torch.distributed.checkpoint instead
    warnings.warn(

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
================================================================================================= 17 passed, 5 skipped, 4 warnings in 1.63s ==================================================================================================

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