Update test and doc versions

[maltesander]

Description

• Add: 3.4.1
• Mark 3.4.0 as deprecated

Part of stackabletech/docker-images#1018

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
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] CRD documentation for all fields, following the [style guide](https://docs.stackable.tech/home/nightly/contributor/docs/style-guide).
- [ ] Helm chart can be installed and deployed operator works
- [ ] Integration tests passed (for non trivial changes)
- [ ] Changes need to be "offline" compatible

# Reviewer
- [x] (Integration-)Test cases ~added~ : dimensions updated
- [x] Changelog updated
- [x] 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

[Techassi]

Also, I would avoid the fixes keyword in the PR description, because that will auto-close the tracking issue. And there are most likely open tasks which are not done yet.

I will edit the description accordingly.

[adwk67]

thanks! - LGTM