Move Feast to pyproject.toml instead of setup.py

Is your feature request related to a problem? Please describe.
Can't install PyTorch in CI using setup.py

Describe the solution you'd like
Migrate to pyproject.toml and keep all extra

Blocks:

• Add Docling to Feast #5037
• Introduce Feast NLP/LLM Add-On #4964
• Google Summer of Code: Production RAG Application #4979

Describe alternatives you've considered
N/A

Additional context
N/A