Add Python 3.13, drop Python 3.8, update tool versions, add twinecheck #179

	name: Tests
	on: [push, pull_request]

	jobs:
	tests:
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	matrix:
	python-version: ["3.9", "3.10", "3.11", "3.12", "3.13", "pypy3.10"]

	steps:
	- uses: actions/checkout@v4

	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}

	- name: Run tests
	run: \|
	pip install -U pip
	pip install -U tox
	tox -e py

	- name: Upload coverage report
	run: bash <(curl -s https://codecov.io/bash)

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