Do not require JsonSubType annotation for sealed classes

[sahil-ramagiri]

Description of Changes

1. SpringDocSealedClassModule.java
   • Provides swagger and jackson with the ability to introspect annotations and resolve subclasses from the permits list of sealed classes.
   • Ensures that subclasses are correctly identified without the need for JsonSubType annotations.
2. SpringDocConfiguration.java
   • Registers the new SpringDocSealedClassModule with objectmapper.
3. API Tests 224, 225
   • Includes polymorphic deserialization tests to verify functionality without JsonSubType annotations.

Important Note

• This PR requires the following PR on Swagger to be merged first: Fix: Avoid caching AnnotationIntrospector to support custom module loading swagger-api/swagger-core#4728
• Swagger caches the annotation introspector, so modules configured after Swagger are not considered in Swagger's subclass resolving logic.
• This also implies that the existing SpringDocRequiredModule may be flaky and might not work if SpringDoc is configured after Swagger.

[bnasslahsen]

@sahil-ramagiri,

Your PR is still in draft mode.
Are you willing to finish it, or we need to close it ?

[sahil-ramagiri]

@sahil-ramagiri,

Your PR is still in draft mode. Are you willing to finish it, or we need to close it ?

@bnasslahsen This is dependent on this other issue in swagger-core. I am trying to get their attention but failing to do so. What do you suggest?

swagger-api/swagger-core#4744
swagger-api/swagger-core#4728

[bnasslahsen]

@sahil-ramagiri,

Just try to ping them again, no worries

[bnasslahsen]

i see

[sahil-ramagiri]

@bnasslahsen The latest release of swagger-core includes my fixes. This PR is finally ready to be merged. Please review.