OCPBUGS-32775#update requirements

[brendan-daly-red-hat]

Versions: 4.16+

Issue: https://issues.redhat.com/browse/OCPBUGS-32775

Link to docs preview:

• https://78357--ocpdocs-pr.netlify.app/openshift-enterprise/latest/machine_management/adding-rhel-compute.html#rhel-compute-requirements_adding-rhel-compute
• https://78357--ocpdocs-pr.netlify.app/openshift-enterprise/latest/machine_management/more-rhel-compute.html#rhel-compute-requirements_more-rhel-compute
• https://78357--ocpdocs-pr.netlify.app/openshift-enterprise/latest/post_installation_configuration/node-tasks.html#rhel-compute-requirements_post-install-node-tasks

QE review:

• [ ] QE has approved this change.

Additional information: