Update pytest requirement from <8,>=7 to >=7,<9 #351

Job	Run time
CI linters via Tox (lintreadme)	35s
cwltest release test	2m 54s
CI linters via Tox (pydocstyle)	21s
CI tests via Tox (3, 8, lint)	17s
CI tests via Tox (3, 8, unit)	29s
CI tests via Tox (3, 8, mypy)	30s
CI tests via Tox (3, 8, bandit)	13s
CI tests via Tox (3, 9, lint)	17s
CI tests via Tox (3, 9, unit)	12s
CI tests via Tox (3, 9, mypy)	13s
CI tests via Tox (3, 9, bandit)	16s
CI tests via Tox (3, 10, lint)	19s
CI tests via Tox (3, 10, unit)	51s
CI tests via Tox (3, 10, mypy)	35s
CI tests via Tox (3, 10, bandit)	13s
CI tests via Tox (3, 11, lint)	21s
CI tests via Tox (3, 11, unit)	50s
CI tests via Tox (3, 11, mypy)	33s
CI tests via Tox (3, 11, bandit)	13s
CI tests via Tox (3, 12, lint)	17s
CI tests via Tox (3, 12, unit)	49s
CI tests via Tox (3, 12, mypy)	48s
CI tests via Tox (3, 12, bandit)	16s
	12m 22s

Provide feedback