health: move to mypy #762

	name: pytype validation

	on:
	push:
	branches: [ main ]
	pull_request:

	jobs:
	build:
	runs-on: ubuntu-latest
	timeout-minutes: 20
	strategy:
	matrix:
	python-version: ['3.9']
	steps:
	- uses: actions/checkout@v4
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install dependencies
	run: \|
	pip install -U pip
	pip install -r requirements/testing.txt
	pip install -r requirements/optional.txt
	# As pytype can change its behavior in newer versions, we manually upgrade it
	# 2023.9.11 fails due to errors that only happen on GH Actions
	pip install "pytype==2023.5.24"
	- name: Run pytype
	run: \|
	pytype slack_sdk/

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