Use CPU-only PyTorch wheels in uv lock

[DingmaomaoBJTU]

Summary

• Configure uv to resolve torch and torchvision from the CPU-only PyTorch index only for the Linux x86_64 resolution environment used by docs setup.
• Keep Windows AMD64 torch and torchvision on the default PyPI wheels.
• Regenerate uv.lock to remove CUDA/NVIDIA/Triton packages while preserving reproducible Linux docs locking.
• Add a lockfile guard test to prevent CUDA/NVIDIA packages from returning.

Validation

• uv lock --locked
• uv run --no-project --with ruff ruff check tests\unit\test_uv_lock.py
• uv run --no-project --with pytest --with pytest-cov --with pytest-timeout python -m pytest --confcutdir=tests\unit tests\unit\test_uv_lock.py -q
• rg -i "cuda|cudnn|nvidia|cublas|cufft|curand|cusolver|cusparse|nccl|nvjitlink|nvtx|triton" uv.lock returns no matches