Correctly resolve nullability from openapi

[Beny406]

Currently when using OpenAPI handler nullability in the schema is resolved based on open api spec field required but it should be based on field nullable. More detailed discussion in openapi-to-graphql repo IBM/openapi-to-graphql#359

Difference:
required => field needs to be there
nullable => field can have a value of null

[ardatan]

In GraphQL, we don't have undefined so when someone asks for a field that is not available in the response, GraphQL returns null. So I think it is fine to have non-nullability per required.

But if nullable is true and that field is defined under required, it should be still nullable for GraphQL.
And if nullable is false, it should be nonnullable for GraphQL.

I'll try to create a PR for it.
Thanks for pointing that.

[ardatan]

When I check the code, it seems to be available in the latest version. Closing this issue for now. Please let us know if it doesn't work as expected on your end.

[FGoessler]

This issue seems to be back. See the issue with more details here: #6560

There is also an open PR that should hopefully fix this: #6561