Update Confluent.Kafka library to version 1.9.2

[jakob-nielsen-dfds]

Includes enhancements and fixes since 1.8.2 and a reference to librdkafka 1.9.2 which includes an Apple M1 build.

For details see:

• Version referenced: https://github.com/confluentinc/confluent-kafka-dotnet/releases/tag/v1.9.2
• Changes from 1.8.2-1.9.2: https://github.com/confluentinc/confluent-kafka-dotnet/releases