Handle nullable types in OpenAPI schemas and add corresponding unit t…

[X39]

This commit provides a basic fix for #6776, unblocking nullable reference types for ASP.Net Core.

It also, magically (aka: as a side effect), makes enums work

[X39]

@microsoft-github-policy-service agree

[lvde0]

@gavinbarron Could you have a look at this?

[snerte]

Please fix this issue

[X39]

Just to note for those in dire need of a fix: building kiota on your own is trivial, after that, just refer to the built version, rather than the installed one by path (aka the .../kiota/bin/release/kiota.exe one)

That is what I am doing right now

[StefanOverHaevgRZ]

@baywet What do we need to get this merged?

[baywet]

I have transitioned to a new team back in August 2025 and won't be replying to this issue/pull request moving forward. Thank you for your understanding.

@gavinbarron and @adrian05-ms to take over