Generated untyped JSON is not handled by OpenAPI spec parser

[sbreatnach]

👋 When attempting to deserialise the OpenApi type from a simple JSON spec generated by aide, it fails with the error data did not match any variant of untagged enum ReferenceOr. FWIW the same spec is parsed without issue by redocly.

This is the spec that's failing:

{
  "openapi": "3.1.0",
  "info": {
    "title": "Test Integration",
    "description": "Good stuff.",
    "version": ""
  },
  "paths": {
    "/v1": {
      "get": {
        "responses": {
          "200": {
            "description": "",
            "content": { "application/json": { "schema": true } }
          },
          "500": { "description": "Internal server error" }
        }
      }
    }
  },
  "components": {}
}

I've created a simple repo to show how I'm generating this spec with aide and a test to reproduce the issue.
Apologies if this has been reported elsewhere, I couldn't find any existing issues on this.