chore!: Upgrade to schemars 1.0, kube 2.0 and k8s-openapi 0.26

[sbernauer]

Description

https://github.com/kube-rs/kube/releases/tag/2.0.0
https://graham.cool/schemars/migrating/

During the bump I noticed a regression in kube 2.0.0 and created kube-rs/kube#1821.
However, we can easily work around this but removing a single rustdoc comment, which didn't show up in the CRD in the first place. It's in crates/stackable-operator/src/product_logging/spec.rs.

I tested this change by bumping op-rs in zookeeper-operator and smoke tests passed.

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.
• 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.
• 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

[NickLarsenNZ]

LGTM