Update black requirement to allow newer versions #913

Job	Run time
cwl-utils release test	51s
CI linters via Tox (lint-readme)	23s
CI tests via Tox (3, 9, lint)	1s
CI linters via Tox (pydocstyle)	17s
CI tests via Tox (3, 9, unit)	1s
CI tests via Tox (3, 9, bandit)	1s
CI tests via Tox (3, 9, mypy)	1s
CI tests via Tox (3, 10, lint)	11s
CI tests via Tox (3, 10, unit)	15s
CI tests via Tox (3, 10, bandit)	15s
CI tests via Tox (3, 10, mypy)	14s
CI tests via Tox (3, 11, lint)	12s
CI tests via Tox (3, 11, unit)	11s
CI tests via Tox (3, 11, bandit)	15s
CI tests via Tox (3, 11, mypy)	13s
CI tests via Tox (3, 12, lint)	9s
CI tests via Tox (3, 12, unit)	1s
CI tests via Tox (3, 12, bandit)	14s
CI tests via Tox (3, 12, mypy)	2s
CI tests via Tox (3, 13, lint)	1s
CI tests via Tox (3, 13, unit)	1s
CI tests via Tox (3, 13, bandit)	1s
CI tests via Tox (3, 13, mypy)	1s
	3m 51s

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