logging-collector-logs-writer clusterrole is not required to be created manually

- Inside `About Logging 6.0` [1]  section in `Quick Start` [2] , the step number: 4, Create a ClusterRole for the collector: is not required.

[1] https://docs.openshift.com/container-platform/4.16/observability/logging/logging-6.0/log6x-about.html
[2] https://docs.openshift.com/container-platform/4.16/observability/logging/logging-6.0/log6x-about.html#quick-start

- In step 4, it has been mentioned that the user needs to create the ClusterRole `logging-collector-logs-writer` but this ClusterRole is created automatically by the Loki operator and it is not required to create it manually.

- This ClusterRole was also made available with the `Loki Operator 5.9` version.
- Here is jira [3] for reference:
[3] https://issues.redhat.com/browse/LOG-5967 

- Hence step 4 needs to be omitted from documentation:

------
4. Create a ClusterRole for the collector:
~~~
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: logging-collector-logs-writer
rules:
- apiGroups:
  - loki.grafana.com
  resourceNames:
  - logs
  resources:
  - application
  - audit
  - infrastructure
  verbs:
  - create
~~~

Author: prithvipatil97

observability/logging/logging-6.0/log6x-about.adoc

@@ -74,27 +74,6 @@ spec:
 $ oc create sa collector -n openshift-logging
 ----
 
-. Create a `ClusterRole` for the collector:
-+
-[source,yaml]
-----
-apiVersion: rbac.authorization.k8s.io/v1
-kind: ClusterRole
-metadata:
-  name: logging-collector-logs-writer
-rules:
-- apiGroups:
-  - loki.grafana.com
-  resourceNames:
-  - logs
-  resources:
-  - application
-  - audit
-  - infrastructure
-  verbs:
-  - create
-----
-
 . Bind the `ClusterRole` to the service account:
 +
 [source,shell]