Fix MLX dependency version from 0.22.0 to 0.22.1

[suyashbhawsar]

Summary

• Updates MLX version from 0.22.0 to 0.22.1 in setup.py
• Fixes installation error where mlx==0.22.0 is not available on PyPI

Problem

When running uv pip install -e . or source install.sh, the installation fails with:

ERROR: Could not find a version that satisfies the requirement mlx==0.22.0 (from exo)
ERROR: No matching distribution found for mlx==0.22.0

Solution

Updated the MLX version requirement from 0.22.0 to 0.22.1, which is available on PyPI.

Test plan

• Verify uv pip install -e . works without errors
• Verify source install.sh completes successfully
• Confirm MLX functionality remains intact