Fix installation issues with PyTorch and coal_openmp_wrapper

[ZeYuan06]

This PR addresses two installation issues:

1. PyTorch installation

   • Changed installation command from

     conda install pytorch==2.2.2 pytorch-cuda=12.1 -c pytorch -c nvidia

     to

     pip install torch==2.2.2+cu121 -f https://download.pytorch.org/whl/torch_stable.html

   • Reason: Installing via conda caused

     undefined symbol: iJIT_NotifyEvent
     

     error, while the pip installation works correctly.

2. coal_openmp_wrapper compilation

   • Updated setup.py to use

     extra_compile_args = ["-std=c++14"]

   • Reason: Without explicitly specifying -std=c++14, compilation fails with C++ standard-related errors.

Impact:

• Ensures a smooth installation process without runtime or compilation errors.
• Improves developer experience when setting up the environment.