bring back kafka as a dev dependency

[alexanderankin]

No description provided.

[totallyzen]

actually, as I understood testcontainers#351 we want to actively not make it a dependency because then people can choose between python-kafka and confluent-kafka for themselves.

I think we can close this and move on with the original PR 🙏

[gudjonragnar]

Yes, the dependency is only there initially to implement the waiting logic, as far as i can see.

[totallyzen]

I did another round, actually you do need it for running the tests too.

So the simplest thing to do for right now is to add python-kafka as a dev dependency.
@alexanderankin added it as an optional dependency too, maybe no need for the latter, just the former.

@gudjonragnar would you please make this change for us on your original PR? Just to make the tests pass. 🙏

[gudjonragnar]

I have added it back as a dev dependency on the original PR 👍 . Will close this one.