fix: Add V100 (older) GPU Support for Mistral 7b Models

[xihajun]

What does this PR do?

Introduction

This PR introduces changes that significantly improve support for running Mistral 7b models on V100 GPU architectures. By update the latest transformers package, we ensure both compatibility and performance for users with V100 GPUs.

Changes

• Altered the model instantiation logic in the scenario where the model type is 'mistral'.
• In environments where FLASH_ATTENTION is not available, the system defaults to using CausalLM. This ensures that Mistral models remain operational even without Flash Attention support.

Impact

These updates are particularly beneficial for users with V100 GPU architectures, which previously faced compatibility issues due to flash-attention package limitations. With these changes, we can expand our hardware support, reduce barriers to entry, and streamline the user experience for a significant segment of our user base.

Additional Notes

The transformers package has been updated to version 4.35.2, which now includes support for Mistral models. This update is essential since the flash-attention package does not support V100 GPUs, as discussed in Dao-AILab/flash-attention#148.

Testing

• Comprehensive tests have been conducted to ensure that Mistral models perform as expected on V100 GPUs.
• Additional benchmarks have been added to compare the performance on V100 GPUs with previous versions.

I invite reviewers to pull this branch, test rigorously with V100 GPUs, and provide feedback on any aspects of this enhancement.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you read the contributor guideline,
  Pull Request section?
• Was this discussed/approved via a Github issue or the forum? Please add a link
  to it if that's the case.
  NotImplementedError: Mistral model requires flash attention v2 #1253
  NotImplementedError: Mistral model requires flash attention v2 #1208
  V100 raiseError that may be too restrictive #319
• Did you make sure to update the documentation with your changes? Here are the
  documentation guidelines, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review?

@abhijithnair1