Bump actions/checkout from 3 to 4 #1717

	name: CI

	on:
	push:
	branches:
	- master
	pull_request:
	schedule:
	# run CI every day even if no PRs/merges occur
	- cron: "0 12 * * *"

	concurrency:
	group: ci-${{ github.ref }}
	cancel-in-progress: true

	jobs:
	lint:
	runs-on: ubuntu-latest
	steps:
	- name: Install LLVM
	run: \|
	wget https://apt.llvm.org/llvm.sh
	chmod +x llvm.sh
	sudo ./llvm.sh 17
	sudo apt install -y libpolly-17-dev
	- uses: actions/checkout@v4
	- name: Format
	run: cargo fmt && git diff --exit-code
	- name: Lint
	run: cargo clippy
	- name: Cargo sort
	run: \|
	cargo install cargo-sort
	cargo sort -c
	test:
	runs-on: ubuntu-latest
	steps:
	- name: Install LLVM
	run: \|
	wget https://apt.llvm.org/llvm.sh
	chmod +x llvm.sh
	sudo ./llvm.sh 17
	sudo apt install -y libpolly-17-dev
	- uses: actions/checkout@v4
	with:
	submodules: recursive
	- name: Unit tests
	run: cargo test
	- name: Integration tests
	run: \|
	cargo build --release
	cd tests
	./run_tests.sh

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