PYTHON-4805 Migrate test_connections_survive_primary_stepdown_spec.py to async

[sleepyStick]

Note: I tried to add async_ensure_all_connected to /test/asynchronous/helpers.py but was running into some issues (circular imports I think?) so that's why I decided to just keep it in test/utils.py but happy to look into it again, if needed.

[NoahStapp]

Note: I tried to add async_ensure_all_connected to /test/asynchronous/helpers.py but was running into some issues (circular imports I think?) so that's why I decided to just keep it in test/utils.py but happy to look into it again, if needed.

What's the specific error you were getting?

[sleepyStick]

Note: I tried to add async_ensure_all_connected to /test/asynchronous/helpers.py but was running into some issues (circular imports I think?) so that's why I decided to just keep it in test/utils.py but happy to look into it again, if needed.

What's the specific error you were getting?

test/__init__.py:31: in <module>
    from test.helpers import (
test/helpers.py:40: in <module>
    from test.utils import wait_until
test/utils.py:33: in <module>
    from test import client_context, db_pwd, db_user
E   ImportError: cannot import name 'client_context' from partially initialized module 'test' (most likely due to a circular import) (/Users/iris.ho/GitHub/mongo-python-driver/test/__init__.py)```



edit: okay it is a circular import
`test/__init__` tries to import from `helpers`, `helpers` tries to import `wait_until` or `async_wait_until` from `utils`. and utils wants to load something from `test`

And this occurs when i try to move the func into `helpers` because `ensure_all_connected`/`async_ensure_all_connected`, uses `wait_until`/`async_wait_until`..

[NoahStapp]

Note: I tried to add async_ensure_all_connected to /test/asynchronous/helpers.py but was running into some issues (circular imports I think?) so that's why I decided to just keep it in test/utils.py but happy to look into it again, if needed.

What's the specific error you were getting?

test/__init__.py:31: in <module>
    from test.helpers import (
test/helpers.py:40: in <module>
    from test.utils import wait_until
test/utils.py:33: in <module>
    from test import client_context, db_pwd, db_user
E   ImportError: cannot import name 'client_context' from partially initialized module 'test' (most likely due to a circular import) (/Users/iris.ho/GitHub/mongo-python-driver/test/__init__.py)```



edit: okay it is a circular import
`test/__init__` tries to import from `helpers`, `helpers` tries to import `wait_until` or `async_wait_until` from `utils`. and utils wants to load something from `test`

And this occurs when i try to move the func into `helpers` because `ensure_all_connected`/`async_ensure_all_connected`, uses `wait_until`/`async_wait_until`..

Got it, leaving it in utils is fine for now.