Label `kubernetes.io/cluster-trust-bundle-version` not documented

[sftim]

This is a Bug Report

Problem:
Prompted by https://github.com/kubernetes/enhancements/pull/3913/files#r1142389497, I'm suggesting we might
need to document the label kubernetes.io/cluster-trust-bundle-version

Proposed Solution:

1. Check if this label is used in any shipped Kubernetes code. If it is, even behind a feature gate, we must document it.
2. If so, get it registered and documented.

Page to Update:
https://kubernetes.io/docs/reference/labels-annotations-taints/

Additional Information:
/language en

[Shubham82]

/sig auth

[stlaz]

/triage accepted
in case the enhancement merges and the label is added

[coder12git]

/assign

[coder12git]

Hey @sftim , according to above comment, seems like i can work on this issue only when this PR merges, is it?

[sftim]

Here's what we need to do, right now:

1. Check if this label is used in any shipped Kubernetes code. If it is, even behind a feature gate, we must document it.
2. If so, get it registered and documented.

Maybe the first step ends with finding that the label isn't used; if so, we're done (for now).