Why is openapi-generator-maven-plugin generating @JsonAdapter for enum instead of @JsonSubTypes for polymorphic deserialization?

Question

I am using the openapi-generator-maven-plugin to generate code for my OpenAPI project. However, I've noticed that when it comes to generating enums representing a polymorphic type, it uses @JsonAdapter instead of @JsonTypeInfo and @JsonSubTypes.

For example, the generated code looks like this:

public class Animal {

  @JsonAdapter(TypeEnum.Adapter.class)
  public enum TypeEnum {
    CAT("CAT"),
    
    DOG("DOG");

    private String value;
}

Instead of what I expected, which would include @JsonTypeInfo and @JsonSubTypes annotations for polymorphic deserialization:

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME,
    include = JsonTypeInfo.As.EXISTING_PROPERTY,
    property = "type",
    visible = true )
@JsonSubTypes( {
    @JsonSubTypes.Type( value = Cat.class, name = "CAT" ),
    @JsonSubTypes.Type( value = Dog.class, name = "DOG" ),
} )
public class Animal {
    

Why does the openapi-generator-maven-plugin use @JsonAdapter for enums instead of @JsonTypeInfo and @JsonSubTypes for polymorphic deserialization? Is there a specific configuration or option that I might be missing?

Example Project

I have created an example GitHub project that reproduces this behavior. Feel free to investigate the project to better understand the issue.

The stubs are generated from a YAML definition file:

openapi: '3.0.3'
info:
  version: '1.0.0'
  title: 'FooService'
components:
  schemas:
    Zoo:
      type: object
      properties:
        animals:
          type: array
          items:
            $ref: '#/components/schemas/Animal'
    Animal:
      type: object
      required:
        - type
      properties:
        type:
          type: string
          enum: [CAT, DOG]
      discriminator:
        propertyName: type
        mapping:
          CAT: "#/components/schemas/Cat"
          DOG: "#/components/schemas/Dog"
    Cat:
      allOf:
        - $ref: "#/components/schemas/Animal"
        - type: object
          properties:
            purrs:
              type: boolean
    Dog:
      allOf:
        - $ref: "#/components/schemas/Animal"
        - type: object
          properties:
            barks:
              type: boolean

Thank you for your assistance!