Tests: Replace unmaintained Bitnami Legacy Kafka image in testcontainers

[igor-soldev]

Description

I noticed that bulkerapp/app/testcontainers/kafka/docker-compose.yml utilizes the bitnamilegacy/kafka:3.7.1 image.

Since Bitnami has moved these images to a legacy repository, they are effectively frozen.

Proposed Solution

I suggest replacing it with the actively maintained alternative: soldevelo/kafka:3.7.1.

This image is a drop-in replacement that preserves the /opt/bitnami/... directory structure and supports the standard environment variables (like ALLOW_ANONYMOUS_LOGIN) used in your configuration. This ensures the test environment remains secure and functional without requiring changes to the setup.

I can submit a quick PR to update this image reference.

[igor-soldev]

Just a friendly ping on this.

Relying on a frozen legacy image creates a risk of future CI failures. The fix is effectively a one-line change that secures the test pipeline.

Would you like me to submit the PR?