Polymorphism issue

Description

When using polymorphism, the JsonSubType is duplicated, like on this example:

@JsonIgnoreProperties(
  value = "type", // ignore manually set type, it will be automatically generated by Jackson during serialization
  allowSetters = true // allows the type to be set during deserialization
)
@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type", visible = true)
@JsonSubTypes({
  @JsonSubTypes.Type(value = CurrencyContextValue.class, name = "CurrencyContextValue"),
  @JsonSubTypes.Type(value = DateTimeContextValue.class, name = "DateTimeContextValue"),
  @JsonSubTypes.Type(value = CurrencyContextValue.class, name = "currency"),
  @JsonSubTypes.Type(value = DateTimeContextValue.class, name = "date_time"),
})

In this example the JsonSubTypes.Type annotation is duplicated.
If I remove the allOf on CurrencyContextValue and on DateTimeContextValue I have no issue.
It seem that the allOf don't use the discriminator field. I can't find any solution.

Swagger-codegen version

I use the gradle plugin org.openapitools:openapi-generator-gradle-plugin:6.4.0

Swagger declaration file content or url

CurrencyContextValue:
      required:
        - currency
      type: object
      example:
        type: currency
        currency: EUR
      allOf:
        - $ref: '#/components/schemas/WhatsAppContextValue'
        - type: object
          properties:
            currency:
              type: string
    DateTimeContextValue:
      required:
        - dateTime
      type: object
      example:
        type: date_time
        dateTime: '2022-10-10T10:10:10.000'
      allOf:
        - $ref: '#/components/schemas/WhatsAppContextValue'
        - type: object
          properties:
            dateTime:
              type: string
              format: date-time
    WhatsAppContext:
      type: object
      properties:
        header:
          type: array
          items:
            oneOf:
              - $ref: '#/components/schemas/CurrencyContextValue'
              - $ref: '#/components/schemas/DateTimeContextValue'
            discriminator:
              propertyName: type
      description: The context is used to fill template variables.
    WhatsAppContextValue:
      required:
        - type
      type: object
      properties:
        type:
          type: string
      discriminator:
        propertyName: type
        mapping:
          currency: '#/components/schemas/CurrencyContextValue'
          date_time: '#/components/schemas/DateTimeContextValue'

This swagger is generated from java annotation using these class:

@JsonTypeInfo(
    use = JsonTypeInfo.Id.NAME,
    property = "type"
)
@JsonSubTypes({
    @JsonSubTypes.Type(value = WhatsAppContextValue.TextContextValue.class, name = "text"),
    @JsonSubTypes.Type(value = WhatsAppContextValue.CurrencyContextValue.class, name = "currency"),
    @JsonSubTypes.Type(value = WhatsAppContextValue.DateTimeContextValue.class, name = "date_time")
})
@Schema(
    name = "WhatsAppContextValue",
    discriminatorProperty = "type",
    discriminatorMapping = {
        @DiscriminatorMapping(value = "text", schema = WhatsAppContextValue.TextContextValue.class),
        @DiscriminatorMapping(value = "currency", schema = WhatsAppContextValue.CurrencyContextValue.class),
        @DiscriminatorMapping(value = "date_time", schema = WhatsAppContextValue.DateTimeContextValue.class)
    }
)
public sealed interface WhatsAppContextValue 

Thanks for you help

Reproduce the generated Java annotations with the openapi-generator-gradle-plugin at version 6.4.0 using the supplied schemas and Java annotations. Trace how allOf and discriminator mappings are processed during Java model generation, then compare the generated JsonSubTypes entries with the currency and date_time mappings. Done means the subtype annotations are not duplicated.