Fix/unit test 3.2 (#726)

.github/workflows/pytest_cpu_gha_runner.yaml

src/llama_recipes/configs/datasets.py

src/llama_recipes/datasets/samsum_dataset.py

src/llama_recipes/finetuning.py

src/tests/conftest.py

src/tests/datasets/test_custom_dataset.py

src/tests/datasets/test_grammar_datasets.py

src/tests/datasets/test_samsum_datasets.py

src/tests/test_batching.py

src/tests/test_chat_completion.py

src/tests/test_finetuning.py

src/tests/test_train_utils.py

src/tests/utils.py