resolveFully breaks 3.0 spec for headers via $ref in request and response

Given the following files:

openapi: 3.0.3
info:
  title: Sample API
  version: 1.0.0
paths:
  /users/:
    get:
      parameters:
        - $ref: 'headers.yml#/XRequestId'
      responses:
        '200':
          description: Ok
          headers:
            X-Request-Id:
              $ref: 'headers.yml#/XRequestId'

and

XRequestId:
  in: header
  name: X-Request-Id
  schema:
    type: string
  required: false

		OpenAPIV3Parser parser = new OpenAPIV3Parser();
		ParseOptions options = new ParseOptions();
		options.setResolveFully(true);

		var api = parser.read(file, null, options);
		String content = Yaml.pretty(api);

the output will contain a $ref that cannot be resolved:

openapi: 3.0.3
info:
  title: Sample API
  version: 1.0.0
servers:
- url: /
paths:
  /users/:
    get:
      parameters:
      - name: X-Request-Id
        in: header
        required: false
        schema:
          type: string
      responses:
        "200":
          description: Ok
          headers:
            X-Request-Id:
              $ref: '#/components/headers/XRequestId'
components:
  parameters:
    XRequestId:
      name: X-Request-Id
      in: header
      required: false
      schema:
        type: string

I know the in: is not valid for responses, but swagger-ui seems to be fine with it.

Surprisingly using version: 3.1.0 fixes that thing, unfortunately openapi-generator is not yet ready for that...

Start with the supplied Java reproduction using OpenAPIV3Parser and ParseOptions.setResolveFully(true), together with the two YAML files. Inspect how the request parameter and response header $ref values are resolved, then verify that the generated output contains no unresolved response-header reference while preserving the OpenAPI 3.0.3 structure.