Refactor void fraction out of solver #666

	#Heavily inspired by the deal.II version of this workflow
	#https://github.com/dealii/dealii

	name: Clang tidy

	on:
	push:
	# Runs on every push on master branch
	branches:
	- master
	# Runs on every push on master branch. If a push contains multiple commits, it will be ran on the latest one.
	pull_request:
	paths-ignore:
	- 'doc/**'
	- 'contrib/**'

	# Cancels running instances when a pull request is updated by a commit
	concurrency:
	group: ${{ github.workflow }}-${{ github.event.pull_request.number \|\| github.ref \|\| github.run_id }}
	cancel-in-progress: true

	env:
	COMPILE_JOBS: 4

	jobs:
	tidy:
	name: tidy
	runs-on: [ubuntu-22.04]

	strategy:
	fail-fast: false
	matrix:
	dealii_version: ["master"]

	# Run steps in container of dealii's master branch
	#container:
	# image: dealii/dealii:${{ matrix.dealii_version }}-focal
	# options: --user root

	steps:
	- name: Setup
	run: \|
	# Since dealii image doesn't include Node.js, we'll install it
	sudo apt-get install -y software-properties-common
	sudo add-apt-repository ppa:ginggs/deal.ii-9.5.1-backports
	sudo apt-get update
	sudo apt-get install -y --no-install-recommends nodejs \
	clang-12 \
	clang-tidy-12 \
	numdiff \
	libboost-all-dev \
	libcgal-dev \
	libp4est-dev \
	trilinos-all-dev \
	petsc-dev \
	libmetis-dev \
	libhdf5-mpi-dev \
	deal.ii

	# Checks-out Lethe with branch of triggering commit
	- name: Checkout code
	uses: actions/checkout@v2

	- name: Tidy
	run: \|
	mkdir build
	cd build
	export PATH=/usr/lib/llvm-12/share/clang/:$PATH
	../contrib/utilities/run_clang_tidy.sh ..

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