using a null mapping looses the constraints

[hauner]

using a null mapping:

openapi-processor-mapping: v7

options:
  bean-validation: true

map:
  paths:
    /foo:
      null: org.openapitools.jackson.nullable.JsonNullable

on a property

      properties:
        bar:
          nullable: true
          type: string
          maxLength: 4

doesn't add the constraint to the generated property.