How to block sourced requisitions from being canceled

Summary:
How to block requesters to cancel their requisitions that are already sourced into POs.

Content (please ensure you mask any confidential information):

A requester created a punchout requisition, approved and then sourced into a PO by the procurement manager.
The requester later canceled the requisition, which in turn caused the PO to be canceled as well.

Is there a way to prevent the requester from canceling a requisition once it has been sourced into a PO?

We want only the buyer or procurement manager to have the ability to cancel such requisitions.

Version (include the version you are using, if applicable):