Note: Doc team updates the current version of the documentation and the
two previous versions (n-2), but we address *only high-priority, or
customer-reported issues* for -2 releases in support.
Describe the changes in the doc and link to your dev story:

1. - [ ] Mandatory: Add the required version to the Fix version/s field.

2. - [X] Mandatory: Choose the type of documentation change or review.

• [X] We need to update to an existing topic

• [ ] We need to add a new document to an existing section

• [ ] We need a whole new section; this is a function not
  documented before and doesn't belong in any current section

• [ ] We need an Operator Advisory review and approval

• [ ] We need a z-Stream (Errata) Advisory and Release note
  for MCE and/or ACM

3. - [ ] *Mandatory: *Use the following link to open the doc and find where the
documentation update should go. Note: As the feature and doc is
understood and developed, this placement decision may change:

• Published doc: https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.10
• Source: https://github.com/stolostron/rhacm-docs

4. - [ ] Mandatory for GA content:

• [ ] Add steps, the diff, known issue, and/or other important
  conceptual information in the following space:

• [ ] *Add Required access level *(example, *Cluster
  Administrator*) for the user to complete the task:

• [ ] Add verification at the end of the task, how does the user
  verify success (a command to run or a result to see?)

• [ ] Add link to dev story here:

5. - [X] Mandatory for bugs: What is the diff? Clearly define what the
problem is, what the change is, and link to the current documentation. Only
use this for a documentation bug.

In the Observability API reference for MCO objects at  [1] the reference for MultiClusterObservability.spec.advanced.retentionConfig makes reference to a "cleanupInterval" property which nominally controls how often the compactor will delete blocks from storage bucket. However, this property does not appear to be actually be part of the configuration as seen by the CRD as created on cluster, and by the following commit for the upstream repo which remove this reference from it's docs [2].

[1] https://docs.redhat.com/en/documentation/red_hat_advanced_cluster_management_for_kubernetes/2.11/html/apis/apis#rhacm-docs_apis_multiclusterobservability_jsonmulticlusterobservability

[2] https://github.com/stolostron/multicluster-observability-operator/commit/ab6bc2ba13821077de875e81da7d6dff71f9ecca

This task looks to address updating our documentation on docs.redhat.com to reflect the change made in ACM 2.11 in the Observability API.