API Canvas: 204 (no content) responses are not rendered

[ioggstream]

When I

1. Have a '204' response, eg.

openapi: 3.0.1
paths:
  /foo:
    delete:
      description: Deletes a question foo.
      tags:
      - foo
      summary: Deletes a foo.
      responses:
        '204':
           description: foo has been deleted.

2. click on API Canvas

I expect

• a nice "204 No Content" is shown

Instead

• it shows a pair of []