Allow KCP remediation when access to the etcd leader is not possible

### What steps did you take and what happened?

if you stop kubelet on the etcd leader member, this prevents KCP from doing some checks it is expecting to do on the leader - and specifically on the leader -.
This prevents remediation to happen.

### What did you expect to happen?

KCP remediation limitation to be documented
Eventually also the error message could be improved

```
- lastTransitionTime: "2023-03-27T07:39:22Z"
message: 'failed to get etcdStatus for workload cluster wl-antrea: failed to create
etcd client: could not establish a connection to any etcd node: unable to create
etcd client: context deadline exceeded'
reason: RemediationFailed @ Machine/wl-antrea-g4pt2-mrjpl
severity: Error
status: "False"
type: ControlPlaneReady
```

### Cluster API version

main, 1.4.0, older releases

### Kubernetes version

_No response_

### Anything else you would like to add?

_No response_

### Label(s) to be applied

/kind documentation
/area control-plane
/triage accepted