deps: remove unsloth

[nina-xu]

Priority Level

Medium

Task Summary

We've found that unsloth doesn't offer any speed up after enforce_eager in vLLM is set to False (PR #363 ). We can remove this dependency altogether.
More discussions here

Technical Details & Implementation Plan

Make sure to run another slurm sweep on all 3 models (dp disabled) and compare to main

Dependencies

No response