setup to pyproject

[zycalice]

🐛 Bug

test case not passing due to repo install

Need to change from setup.py to pyproject.toml (pypa/setuptools#3214). Could use:
pdm import setup.py

To Reproduce

Steps to reproduce the behavior (always include the command you ran):

https://app.circleci.com/pipelines/github/facebookresearch/metaseq/1949/workflows/f65b30d8-8b65-4fe5-ada9-dbdaa1cec8b1/jobs/2467

Code sample

Expected behavior

Environment

• metaseq Version (e.g., 1.0 or master):
• PyTorch Version (e.g., 1.0)
• OS (e.g., Linux, Windows, MacOS):
• How you installed metaseq (pip, source):
• Build command you used (if compiling from source):
• Python version:
• CUDA/cuDNN version:
• GPU models and configuration:
• Any other relevant information:

Additional context