fix: enable discriminator lookup for java

[WoodyWoodsta]

Adds discriminator lookups for Java oneOf specs. This fixes an issue where the oneOf specs weren't being automatically discriminated.

Related Issue or Design Document

Fixes https://github.com/ory/kratos/issues/3807

Checklist

• [ ] I have read the contributing guidelines and signed the CLA.
• [x] I have referenced an issue containing the design document if my change introduces a new feature.
• [x] I have read the security policy.
• [x] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got approval (please contact security@ory.sh) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [x] I have added the necessary documentation within the code base (if appropriate).

Further comments

[CLAassistant]

All committers have signed the CLA.

[aeneasr]

Awesome, nice find!

[WoodyWoodsta]

Thanks @aeneasr. What is the release schedule of the java sdk? (i.e. when can we expect this change to be published?)

[aeneasr]

The client SDK for Ory Network is released almost every time we release to Ory Network. For Ory OSS we release SDKs alongside releases for the projects

[WoodyWoodsta]

Even for an inop SDK? We'll have to sort out our own Maven repo or do something locally then :D