Disable introspection, returns null in __typename--Dynamic Schema

[ct-porco]

Expected Behavior

"__typename" field is populated when introspection is disabled.

{
  "data": {
    "user": {
      "avatar": {
        "__typename": "Image"
      },
      "__typename": "User"
    }
  }
}

Actual Behavior

"__typename" field is always null when introspection is disabled, which may break queries which return Union types.

{
  "data": {
    "user": {
      "avatar": {
        "__typename": null
      },
      "__typename": null
    }
  },
}

Steps to Reproduce the Problem

1. Use dynamic schema
2. Use schema.disable_introspection()
3. Make a request with __typename

Specifications

• Version: 6.0.3
• Platform: Debian 12 (Bookworm)
• Subsystem: N/A