[Internal]: CCS Permissions update

### Description

So if we apply permissions based on the doc [here](https://www.elastic.co/docs/deploy-manage/remote-clusters/remote-clusters-api-key#_configure_privileges_for_ccs).

I can run into intermittent permission issues due to missing cluster:monitor/async_search/status

For example

```
action [cluster:monitor/async_search/status] is unauthorized for user [test_userapm-dev-ac] with effective roles [kb_usage,remote-search], this action is granted by the cluster privileges [monitor,manage,all]
```

This documentation should be updated to include this privilege so users can actually use Kibana for CCS without intermittent issues.
The documentation should also be updated to include only permissions actually used, as it currently has `read_cross_cluster` which doesn't seem to be necessary.

### Resources

N/A

### Which documentation set does this change impact?

Elastic On-Prem and Cloud (all)

### Feature differences

N/A

### What release is this request related to?

N/A

### Serverless release

N/A

### Collaboration model

The documentation team

### Point of contact.

**Main contact:** Adrian Chen

**Additional Thread**:
[Slack thread](https://elastic.slack.com/archives/C05GZGCK5C4/p1762765487063079)
[Slack thread](https://elastic.slack.com/archives/C0JF80CJZ/p1762767904036889)

**Stakeholders:**

## Action
added by (@georgewallace)
- Follow up on thread to determine the proper outcome
- Potential stopgap
- Update the documentation to include the `cluster:monitor` so folks do not get intermittment timeouts