Fix Mypy error #61

	name: Lint

	on:
	pull_request:
	branches: [ main ]

	jobs:
	pre-commit:
	name: Pre-commit
	runs-on: ubuntu-20.04
	steps:
	- name: Install pre-commit's dependencies
	run: \|
	sudo apt-get update
	sudo apt-get install -q -y --no-install-recommends git python3-pip clang-format-11 cppcheck libxml2-utils wget
	pip3 install pre-commit cpplint
	sudo wget -O /bin/hadolint https://github.com/hadolint/hadolint/releases/download/v2.8.0/hadolint-Linux-x86_64
	sudo chmod +x /bin/hadolint

	- name: Fetch the package's repository
	uses: actions/checkout@v4
	# NOTE: This has to be done after installing pre-commit, s.t. the
	# pre-commit hooks are automatically initialized.

	- name: Get python version for pre-commit cache
	run: echo "PRE_COMMIT_PYTHON_VERSION=$(python -VV \| sha256sum \| cut -d' ' -f1)" >> $GITHUB_ENV

	- name: Setup pre-commit cache sharing
	uses: actions/cache@v4
	with:
	path: ~/.cache/pre-commit
	key: pre-commit\|${{ env.PRE_COMMIT_PYTHON_VERSION }}\|${{ hashFiles('.pre-commit-config.yaml') }}

	- name: Run the pre-commit hooks
	shell: bash
	run: \|
	echo "::add-matcher::./.github/problem-matchers/pre-commit.json"
	PRE_COMMIT_HOME=~/.cache/pre-commit SKIP=no-commit-to-branch pre-commit run --all-files
	echo "::remove-matcher owner=problem-matcher-pre-commit::"

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