fix(examples): seperate torch distributed training code to two scripts

[jingxu9x]

No description provided.

[Copilot]

Pull Request Overview

This PR separates PyTorch distributed training code into two distinct scripts, creating separate implementations for different distributed training backends. The changes extract MPI-based distributed training into a dedicated script while simplifying the original script to use PyTorch's native distributed launcher.

• Creates a new MPI-specific distributed training script (main_with_mpi.py)
• Simplifies the original script to use PyTorch's native distributed environment variables
• Removes manual distributed setup code from the main script in favor of automatic initialization

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
advanced/pytorch-example/main_with_mpi.py	New script implementing MPI-based distributed training with OMPI environment variables
advanced/pytorch-example/main.py	Simplified to use PyTorch's native distributed launcher with standard environment variables