Replace Bitnami Kafka image with a free compatible alternative

[igor-soldev]

The file dockerfiles/devicehive-kafka.Dockerfile currently uses:

FROM docker.io/bitnami/kafka:3.1

Since Bitnami has introduced access restrictions to many of their images, this may cause pull failures for users building or running DeviceHive.

A free, Bitnami-compatible drop-in replacement such as soldevelo/kafka can be used instead. It preserves the /bitnami/... layout, runs as non-root, and tracks upstream Kafka versions.
Link: https://hub.docker.com/r/soldevelo/kafka

If acceptable, I can submit a PR updating this Dockerfile.