CI: allow failure on Amaranth 0.3 builds. #608

	on:
	push:
	pull_request:
	schedule:
	- cron: '0 0 * * *' # test daily against git HEAD of dependencies

	name: CI
	jobs:

	test:
	runs-on: ubuntu-latest
	strategy:
	matrix:
	python-version:
	- '3.8'
	- '3.9'
	- '3.10'
	- '3.11'
	- 'pypy-3.8'
	- 'pypy-3.9'
	# this version range needs to be synchronized with the one in pyproject.toml
	amaranth-version:
	- '0.3'
	- 'git'
	allow-failure:
	- true
	- false
	exclude: # all of these are inverted (this is unfortunately the best way to do this)
	- amaranth-version: '0.3'
	allow-failure: false
	- amaranth-version: 'git'
	allow-failure: true
	continue-on-error: '${{ matrix.allow-failure }}'
	name: "test (${{ matrix.python-version }}, ${{ matrix.amaranth-version }}${{ matrix.allow-failure == 'false' && ', required' }})"
	steps:
	- name: Check out source code
	uses: actions/checkout@v3
	- name: Set up Python
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install Amaranth release
	if: ${{ matrix.amaranth-version != 'git' }}
	run: \|
	pip install 'amaranth==${{ matrix.amaranth-version }}'
	- name: Downgrade MarkupSafe
	if: ${{ matrix.amaranth-version == '0.3' }}
	run: \|
	pip install 'MarkupSafe==2.0.1'
	- name: Install Amaranth from git
	if: ${{ matrix.amaranth-version == 'git' }}
	run: \|
	pip install git+https://github.com/amaranth-lang/amaranth.git
	- name: Test
	run: \|
	python -m unittest discover -t . -s amaranth_boards -p '*.py'

	required: # group all required workflows into one for the required status check
	needs:
	- test
	runs-on: ubuntu-latest
	steps:
	- run: \|
	true

Provide feedback