Koperator does not clean up SSL resources when switching to PLAINTEXT for all listeners

[panyuenlau]

Description

When users configure the Kafka cluster with some SSL listeners (e.g. kafkacluster_with_external_ssl.yaml) to all PLAINTEXT listeners (e.g. https://github.com/banzaicloud/koperator/blob/master/config/samples/kafkacluster_without_ssl.yaml#L52-L66), the Koperator currently does not remove the resources created for SSL listeners.

Expected Behavior

Koperator successfully cleans up all of the resources created for SSL listeners

Actual Behavior

Koperator doesn't clean up any of the resources created for SSL listeners even though they are no longer needed.

Affected Version

<= Koperator v0.24.1

Steps to Reproduce

1. Create a Kafka cluster with kafkacluster_with_external_ssl.yaml
2. Configure all listeners to be PLAINTEXT, e.g. https://github.com/banzaicloud/koperator/blob/master/config/samples/kafkacluster_without_ssl.yaml#L52-L66
3. Check resources created for SSL listeners,KafkaUser, secrets that contain the corresponding certs, etc.

Checklist

• I have read the contributing guidelines
• I have verified this does not duplicate an existing issue