Downgrade DNS errors to warnings

[nightkr]

Description

After some discussion on Slack (https://stackable-workspace.slack.com/archives/C031A5Z9542/p1733999979523619), treating these as errors might be a bit harsh, given that containerdebug is "only" a diagnostics tool.

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

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] 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

[Maleware]

LGTM, modulo checks. Thanks for picking this up right away :)

[nightkr]

Yeah the deny is a separate issue we should look into.

[lfrancke]

I know I'm late here but considering it's a WARN it'd be helpful if we could give users some context.
Like "shit, there is a warning, what does it mean? is it bad for me? what can I do? What does it mean?"

Not sure if that's possible. Treat it as an idea.

[nightkr]

Hmm..