'type' field for component schema is not required

[ffleader1]

A component schema NewUser like this

    NewUser:
      # type: object
      required:
        - username
        - age
      properties:
        username:
          type: string
          description: Name of the pet
        age:
          type: integer
          description: user age

will break.
The reason is that it's missing type: object. However, Oapi V3 Spec does not require type: object to be persented. The properties key make it implicit that the schema is object type.