Remove `setup.py test` fossils

[tseaver]

Based on this morning's setuptools 72.0 helmet fire, I've noted that we still have fossils of the old setup.py test stuff in our packages (test_suite=zope.*.tests, tests_require=[...]. Those should be removed everywhere, just in case they trip up either us our our downstream users.

• test_suite=: https://github.com/search?q=org%3Azopefoundation+%22test_suite%3D%22++NOT+is%3Aarchived&type=code
• tests_require=: https://github.com/search?q=org%3Azopefoundation+%22tests_require%3D%22++NOT+is%3Aarchived&type=code