[Schema Inaccuracy] GitHub App (`integration`) is Nullable

[aayachnes]

Schema Inaccuracy

The integration type in the OpenAPI document is marked nullable, even though there is a nullable-integration type which is equivalent. This means that, according to the OpenAPI document, the GET /apps/{app_slug} API returns null or an integration, which I do not believe is accurate. If this is accurate, please do let me know what the case is where the API returns null, and I would recommend documenting this case in the OpenAPI document.

Expected

The integration type should not have nullable: true set. Because this type is nullable, the TypeScript type (from openapi-types.ts) for the GET /apps/{app_slug} API response is inaccurate, and I have to manually override the type to be non-null.

Reproduction Steps

N/A