website: use pytest parametrize for test_routing_generator()

website: use pytest parametrize for test_routing_generator()

resolves error with recent pytest:

==================================== ERRORS ====================================
____________ ERROR collecting s3tests/functional/test_s3_website.py ____________
'yield' keyword is allowed in fixtures, but not in tests (test_routing_generator)

use https://docs.pytest.org/en/7.1.x/example/parametrize.html instead to
generate a test_routing_generator() for each entry in ROUTING_RULES_TESTS

Signed-off-by: Casey Bodley <cbodley@redhat.com>
(cherry picked from commit d587a4a49983651258f91a8a47b7faf0e7138ec3)