nix: replace nix-shell to flake #32

	name: Path Tracer

	on: [push]

	jobs:
	test:
	name: Lint, check format and test
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v3
	- name: Update apt
	run: sudo apt-get update
	- name: Install lib csfml
	run: sudo apt-get install -y libcsfml-dev
	- name: Install rust
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	components: rustfmt, clippy
	override: true
	- name: Load cached target
	uses: actions/cache@v3
	id: cached-cargo-dependencies
	with:
	path: target/
	key: path-tracer-${{ hashFiles('Cargo.lock') }}
	- name: Check format
	uses: actions-rs/cargo@v1
	with:
	command: fmt
	args: --check
	- name: Clippy check
	uses: actions-rs/clippy-check@v1
	with:
	token: ${{ secrets.GITHUB_TOKEN }}
	args: --all-features -- -D warnings
	- name: Run tests
	uses: actions-rs/cargo@v1
	with:
	command: test
	args: --release --verbose

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