Deprecate ruby-kafka version

[Watson1978]

Is your feature request related to a problem? Please describe.

https://github.com/zendesk/ruby-kafka is no longer active.
So, I think It would be better to recommend using rdkafka instead of ruby-kafka version.

And, It seems that there are cases where you cannot connect to the broker when using ruby-kafka.
Ref. #483

Describe the solution you'd like

When using ruby-kafka, it shows a message recommending rdkafka, etc.

Describe alternatives you've considered

TBD

Additional context

No response