Remap value 'unknown' to 'warning' for KSM 'node.ready' service check

[kaitlavs]

What does this PR do?

Remaps the value of the KSM node.ready service check from 'unknown' to 'warning' when a node enters an unknown state.

Motivation

Additional Notes

Review checklist (to be filled by reviewers)

• Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
• PR title must be written as a CHANGELOG entry (see why)
• Files changes must correspond to the primary purpose of the PR as described in the title (small unrelated changes should have their own PR)
• PR must have changelog/ and integration/ labels attached

[github-actions]

Label changelog/Changed was added to this Pull Request, so the next release will bump major version. Please make sure this is a breaking change, or use the changelog/Fixed label.