docs: update certificate lifetime user guide

[razvan]

Description

Part of: stackabletech/issues#586

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
- [ ] 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

[sbernauer]

Unrelated, but can you please run cargo update -p hashbrown?

[razvan]

Unrelated, but can you please run cargo update -p hashbrown?

$ cargo update -p hashbrown
error: There are multiple `hashbrown` packages in your project, and the specification `hashbrown` is ambiguous.
Please re-run this command with one of the following specifications:
  hashbrown@0.14.5
  hashbrown@0.15.0

[sbernauer]

As the vulnerable version is 0.15.0, you can use cargo update -p hashbrown@0.15.0 as the command suggests.
However, I'm a fan a of simply cargo update to pull in new crate versions in general :)

[sbernauer]

Many thanks!

[lfrancke]

Is this going to be in 25.3 or 24.11.1?

[sbernauer]

25.3