Update single device recipes to enable async checkpointing for intermediate checkpoints

[ankitageorge]

Context

What is the purpose of this PR? Is it to

• [x ] add a new feature
• fix a bug
• update tests and/or documentation
• other (please add here)

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Changelog

What are the changes made in this PR?

• Enable DCP async checkpointing for single device recipes behind the enable_async_checkpointing recipes.
  The recipes changed are lora_dpo_single_device.py, lora_finetune_single_device.py

Test plan

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• run recipe tests via pytest tests -m integration_test
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UX

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• [x ] I did not change any public API
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[pytorch-bot]

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