Drop support for Python 3.6. #468

	name: Ubuntu

	# see https://github.community/t5/GitHub-Actions/How-to-trigger-an-action-on-push-or-pull-request-but-not-both/m-p/35805
	on:
	push:
	branches:
	- main
	pull_request:
	branches:
	- main

	jobs:
	build:

	runs-on: ${{ matrix.os }}

	strategy:
	fail-fast: false
	matrix:
	os: [ubuntu-20.04, ubuntu-22.04]
	python-version: [3.7, 3.8, 3.9, '3.10', '3.11', '3.12', '3.13']

	steps:
	- uses: actions/checkout@v3

	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	allow-prereleases: true

	- name: Show environment
	run: \|
	python --version
	python3 -c "import multiprocessing as m; print('CPUs:', m.cpu_count())"

	- name: Install dependencies
	run: \|
	sudo apt-get -y install minisat python3-pip tox

	- name: Check style
	if: matrix.os == 'ubuntu-22.04' && matrix.python-version == '3.12'
	run: \|
	tox -e style

	- name: Run tests
	run: \|
	tox -e py,slow

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