docs: update OAS for loyalty plugin (#12836)

* updates

* cleanup

* generate OAS

* update links

www/apps/api-reference/specs/admin/components/schemas/AdminGiftCard.yaml

@@ -4,7 +4,6 @@ x-schemaName: AdminGiftCard
 required:
   - line_item
   - customer
-  - invitation
   - id
   - code
   - status
@@ -65,8 +64,6 @@ properties:
     type: string
     title: expires_at
     description: The date the gift card expires at.
-  invitation:
-    $ref: ./AdminGiftCardInvitation.yaml
   created_at:
     type: string
     format: date-time