[OKD] openshift-client and openshift-install download procedures are outdated on 4.16

[pczarnik]

Which section(s) is the issue in?

OKD 4.16 / Installing / Installing on bare metal / Installing a user-provisioned cluster on bare metal

OKD 4.16 / Installing / Installing on a single node / Installing OpenShift on a single node

OKD 4.16 / Installing / Installing on AWS / User-provisioned infrastructure / Preparing to install a cluster

What needs fixing?

Since OKD 4.16 is using CentOS Stream CoreOS (SCOS) instead of Fedora CoreOS (FCOS), appropriate instructions for downloading openshift-client and openshift-install need to be updated.

• https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ needs to be changed to https://mirror.openshift.com/pub/openshift-v4/x86_64/clients/ocp/ and instructions should be adjusted appropriately.
• https://github.com/okd-project/okd/releases/ should be changed to https://github.com/okd-project/okd-scos/releases/