Do not yield on awaitables in tests. (#8193)

changelog.d/8193.misc

tests/api/test_filtering.py

tests/crypto/test_keyring.py

tests/federation/test_complexity.py

tests/handlers/test_typing.py

tests/rest/client/v2_alpha/test_filter.py

tests/storage/test_appservice.py

tests/storage/test_background_update.py

tests/storage/test_end_to_end_keys.py

tests/storage/test_event_push_actions.py

tests/storage/test_main.py

tests/storage/test_registration.py

tests/storage/test_user_directory.py

tests/test_state.py

tests/test_visibility.py