[BUG][Java][Spring] OneOf discriminator seems to ignore type format which causes type mismatch

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

OneOf interfaces that should use string+uri as discriminator only use String, which causes a type mismatch because the discriminator is being generated as URI in the classes.

openapi-generator version

7.5.0

OpenAPI declaration file content or url

https://gist.github.com/Kaemmelot/ad720f03f4f536bb0f54ec281e02479d

Generation Details

java -jar openapi-generator-cli-7.5.0.jar generate -i api.yml -g spring

Steps to reproduce

see Gist above, PetResponse has a wrong type for getPetType()

Related issues/PRs

did not find any

Suggest a fix

It could be that the format of the type is not taken into account when generating such a oneOf interface.

Start with the api.yml from the linked Gist and run the documented openapi-generator-cli 7.5.0 Spring generation command. Inspect the generated PetResponse and its getPetType() method, comparing the OneOf discriminator type with the string+uri types in the generated classes. Done means the discriminator uses a compatible type and the generated code no longer has the reported type mismatch.