How to make Supplier contact id information optional? In 25C it became mandatory.

This question is moved to Self Service PRocurement:

After creating a non catalog request PR (purchase requisition), it doesn't automatically become a PO due to Supplier contact name, address, phone or email missing or being incorrect. There's no notification about this issue to the approver or requester.

How can I make the Supplier contact information optional?

When a contact is not associated with the desired Site, I get this error: POZ-2130160 This is a purchasing site without any active contact.

I've gotten other errors when the contact's name is incorrect.