[REVIEW] remove references to setup.py in docs

[jameslamb]

Proposes removing references to setup.py in this project's docs. This project doesn't use a setup.py file.

How I tested this

On a machine with a couple V100s, ran the following (based on what I see in this project's CI):

docker run \
    --rm \
    --gpus all \
    -v $(pwd):/usr/local/pynvjitlink \
    -w /usr/local/pynvjitlink \
    -it rapidsai/ci-wheel:cuda12.0.1-centos7-py3.9 \
    bash

# installed CTK following this:
# https://github.com/rapidsai/pynvjitlink/blob/56a6d74f365c3e601a503dfd6a58ad4e3fc532c7/ci/build_wheel.sh
yum update -y
yum install -y \
    cuda-toolkit-12-3 \
    epel-release \
    nvidia-driver-latest-dkms

# skipped using sccache, just to avoid having to set up credentials
unset \
    CMAKE_C_COMPILER_LAUNCHER \
    CMAKE_CUDA_COMPILER_LAUNCHER \
    CMAKE_CXX_COMPILER_LAUNCHER

# built a wheel and installed it
python -m pip install -e .

# tested
make -C ./test_binary_generation
pip install pytest
pytest -v ./pynvjitlink/tests

I saw that build succeed and all tests pass.

Notes for Reviewers

In case you're wondering "what is this random contribution"... I recently joined NVIDIA and am working on RAPIDS packaging stuff. Was just poking around this repo and noticed in this in the README.

Thanks for your time and consideration.