Add support for OpenAPI spec 3.2

[SaberStrat]

Is your feature request related to a problem? Please describe.

My problem is that I want to describe an XML schema and generate examples that have an element with attributes and a text-type child element:

<request>
  <signature version="2.0">123abc</signature>
</request>

The result when translating the DAO with JAXB

@Schema
@XmlRootElement(name = "request")
public class Request {
  @XmlElement(name = "signature")
  public Signature signature;

  public class Signature {
    @Schema(example = "2.0")
    @XmlElement(name = "version")
    public String version;

    @Schema(example = "123abc")
    @XmlValue
    public String value;
}

but rendering it with springdoc 2.8.17 and OpenAPI 3.1 gives me the api-docs:

<request>
  <signature version="2.0">
    <value>123abc</value>
  </signature>
</request>

Describe the solution you'd like
The lack of support for this stems from OpenAPI not supporting this as of spec 3.1. There was an issue filed for OpenAPI-Specification OAI/OpenAPI-Specification#630. It was implemented in OAI/OpenAPI-Specification#4592 and released in https://github.com/OAI/OpenAPI-Specification/releases/tag/3.2.0.

So I'd like springdoc to add support for api-docs version 3.2.x.

Describe alternatives you've considered
My alternative for now is to hard-code the example into my api-docs and accept the wrong looking schema until newer OpenAPI spec versions.

[Mattias-Sehlstedt]

Model introspection within springdoc comes from swagger-core, so I believe this functionality thus needs to be implemented there.

[SaberStrat]

Oh, okay. Found and issue for this there already swagger-api/swagger-core#5181.