[enterprise-4.13] Issue in file scalability_and_performance/ztp_far_edge/ztp-preparing-the-hub-cluster.adoc

Description of problem: The AgentServiceConfig CR example in the OCP doc includes a namespace but it's not needed since the CRD is cluster-scoped basis.

Version-Release number of selected component (if applicable): 4.10

How reproducible: Always (doc issue)

Steps to Reproduce: 

1.
2.
3.

Actual results: The AgentServiceConfig CR example in the OCP doc includes a namespace as follows.

apiVersion: agent-install.openshift.io/v1beta1
kind: AgentServiceConfig
metadata:
  name: agent
  namespace: assisted-installer
spec:

Expected results: No namespace is needed in the CR, for instance, shown in the ACM doc.

apiVersion: agent-install.openshift.io/v1beta1
kind: AgentServiceConfig
metadata:
  name: agent
spec:

Additional info: