ci: bump actions/checkout from 2 to 4 #54

	name: Build and Test (Flit)

	on:
	push:
	branches:
	- '**'
	pull_request:
	branches:
	- '**'

	jobs:
	build-and-test-flit:
	runs-on: ubuntu-latest

	steps:
	# Step 1: Check out the repository
	- name: Check out repository
	uses: actions/checkout@v4

	# Step 2: Set up Python
	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: '3.11'

	# Step 3: Install Flit, pytest, pytest-cov, and Coverage
	- name: Install Flit, pytest, pytest-cov, and Coverage
	run: \|
	pip install flit pytest pytest-cov coverage[toml]

	# Step 4: Install dependencies (including dev dependencies)
	- name: Install package (dev extras)
	env:
	FLIT_ROOT_INSTALL: "1"
	run: \|
	flit install --deps develop --extras dev

	# Step 5: Run tests with coverage
	- name: Run tests with coverage
	run: \|
	pytest --cov=gds_fdtd --cov-branch --cov-report=xml

	# Step 6: Upload coverage reports to Codecov
	- name: Upload coverage reports to Codecov
	uses: codecov/codecov-action@v5
	with:
	token: ${{ secrets.CODECOV_TOKEN }}
	slug: SiEPIC/gds_fdtd
	files: coverage.xml
	flags: unittests

Provide feedback