Use a ConfigMap for the prepared logs in the logging test

[siegfriedweber]

Description

Use a ConfigMap for the prepared logs in the logging test

kubectl cp was used to directly copy the prepared logs into the Kafka broker pod, but this fails if the pod is restarting. This pull request creates a ConfigMap with the prepared logs and mounts it into the log path of the vector container.

Definition of Done Checklist

• Not all of these items are applicable to all PRs, the author should update this template to only leave the boxes in that are relevant
• Please make sure all these things are done and tick the boxes

# Author
- [x] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] Code contains useful logging statements
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated. Follows the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs-style-guide).
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added
- [ ] [Roadmap](https://github.com/orgs/stackabletech/projects/25/views/1) has been updated

[siegfriedweber]

:white_check_mark: https://ci.stackable.tech/view/02%20Operator%20Tests%20(custom)/job/kafka-operator-it-custom/63/

OpenSearch Dashboard with prepared logs&_a=(columns:!(level,namespace,cluster,pod,container,message,t2_cluster),filters:!(('$state':(store:appState),meta:(alias:!n,disabled:!f,index:t2-product,key:t2_cluster,negate:!f,params:(query:'3e444678-d5c8-4a6e-adaf-f30f589cb85a'),type:phrase),query:(match_phrase:(t2_cluster:'3e444678-d5c8-4a6e-adaf-f30f589cb85a'))),('$state':(store:appState),meta:(alias:!n,disabled:!f,index:t2-product,key:container,negate:!f,params:(query:prepared-logs),type:phrase),query:(match_phrase:(container:prepared-logs)))),index:t2-product,interval:auto,query:(language:kuery,query:''),sort:!()))