Incorrect kafka example (should not be valid)

### Describe the bug

This example has x- fields in bindings.

https://github.com/asyncapi/spec/blob/master/examples/adeo-kafka-request-reply-asyncapi.yml

But according to docs they are should not exist there, so example is not valid and should be removed.

https://github.com/asyncapi/bindings/blob/master/kafka/README.md
https://github.com/asyncapi/spec-json-schemas/tree/master/bindings/kafka/0.5.0

Start with examples/adeo-kafka-request-reply-asyncapi.yml and compare its bindings with the Kafka binding README and the 0.5.0 schema linked in the issue. Confirm that the x- fields are not valid there, then remove the invalid example and verify it is no longer present.

Written by the indexing model from the issue text.