zstd compression support for Kafka storage

[arnitolog]

Describe the bug
I started to see the error below as soon as I enabled zstd compression on the collector side.
We are on jaeger 1.19.2 and Kafka 2.5.0

{"level":"error","ts":1613990679.9162657,"caller":"kafka/writer.go:58","msg":"zstd compression requires building with cgo enabled","stacktrace":"github.com/jaegertracing/jaeger/plugin/storage/kafka.NewSpanWriter.func2\n\tgithub.com/jaegertracing/jaeger/plugin/storage/kafka/writer.go:58"}

To Reproduce
Steps to reproduce the behavior:

1. configure zstd compression for kafka

Have I missed something? Will upgrade to the latest Jaeger will help here?

[jpkrohling]

If it requires cgo, we will probably remove support for this feature.

[arnitolog]

as far as I can see sarama has switched from cgo to pure Go implementation for zstd in 1.24.0: https://github.com/Shopify/sarama/blob/master/CHANGELOG.md#version-1240-2019-10-09
IBM/sarama#1477

[jpkrohling]

In which case, we might want to bump the dependency. Would you like to give it a try?

[arnitolog]

yeah, will try to build it locally and see how it works