Add black_multi_python workflow. #1

	name: multi-python black check on push and PR
	#
	# Run the black formatting in multiple Python versions
	#
	on: [push, pull_request]

	jobs:
	black-check-multi-python:
	runs-on: ubuntu-latest
	strategy:
	fail-fast: false
	matrix:
	python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
	steps:
	- uses: actions/checkout@v4
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v3
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install black
	- name: Analysing the code with black
	run: \|
	cd python
	black --check --config python/pyproject.toml ../cime_config/SystemTests ../cime_config/buildlib ../cime_config/buildnml

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