Modernize build system to use pyproject.toml and build wheels #821

	name: Charm4py

	on:
	push:
	branches:
	- main
	pull_request:
	schedule:
	- cron: "5 0 * * *" # Runs at 00:05 UTC every day.

	jobs:
	auto_test:
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	python-version: ["3.7", "3.12"]
	# macos-13 is x86_64, macos-14 is arm64
	os: [ubuntu-latest, macos-13, macos-14]
	exclude:
	- os: macos-14 # Python 3.7 does not exist for macos-14
	python-version: "3.7"
	fail-fast: false

	steps:
	- uses: actions/checkout@v4
	with:
	fetch-depth: 0 # Need full repo for 'git describe' used by setup.py
	- name: setup-python
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install dependencies
	run: \|
	pip install setuptools cython cffi greenlet numpy torch torchvision filelock
	if [ ${{ matrix.os }} == 'macos-13' ]; then
	# pypi only distributes torch packages w/ numpy v1 for macos-x86_64
	pip install 'numpy<2'
	fi
	- name: Build Charm++/Charm4py
	run: \|
	git clone https://github.com/charmplusplus/charm charm_src/charm
	export CHARM_EXTRA_BUILD_OPTS="--enable-error-checking"
	export CHARM_BUILD_PROCESSES=2
	export CHARM4PY_BUILD_CFFI=1
	python setup.py build_ext --inplace
	- name: Run auto_test.py
	run: \|
	export PYTHONPATH="$PWD"
	export CHARM4PY_TEST_NUM_PROCESSES=2
	if [ ${{ matrix.os }} == 'macos-13' ]; then
	# Crashes in ray test otherwise
	export OBJC_DISABLE_INITIALIZE_FORK_SAFETY=YES
	fi
	python auto_test.py

Provide feedback