[spring/spring-boot] This spec will generate code correctly

api.yaml

openapi: 3.0.1
info:
  title: Example API
  version: '1.0'
paths:
  /test:
    post:
      requestBody:
        $ref: '#/components/requestBodies/setupReq'
      responses:
        '201':
          description: ok
components:
  requestBodies:
    setupReq:
      content:
        application/json:
          schema:
            type: string

Specification created for openapi-generator #10435 which shows that refs can be used for requestBodies, but only if the requestBody schema is not of type object.