Highlighting for request/response sample/example strings ignores content media type (always JSON highlighting)

Describe the bug
Highlighting for request/response sample/example strings highlights as JSON(ish?) regardless of content type.

Expected behavior
Request/response media type objects allow an example which may be a string or an object. The media-type should determine which (Prism?) highlighting is used. An example for application/x-yaml should be highlighted as YAML, etc.

Minimal reproducible OpenAPI snippet(if possible)
Should hightlight as YAML because content: application/x-yaml has string example. application/x-yaml should govern the highlighting language choice.

openapi: 3.0.3
info: {}
paths:
  /something:
    post:
      operationId: something
      requestBody:
        content:
          application/x-yaml:
            example: |
              ---
              some: # comment
                - 1 value
                - 123 true false null should be a string
                - [1,2,3]
              ---
              dates_look_bad:
                - 2024-03-22T23:04:35.013+00:00  # should be highlighted as a string
                - "2024-03-22T23:04:35.013+00:00"  # quoted so is a string

Screenshots
Redoc renders thusly:

Expected
Should look something like this:

Use the minimal OpenAPI 3.0.3 snippet in this issue as the first reproduction, checking request-body content example rendering and its syntax-highlighting selection. Done means a string example under application/x-yaml is highlighted as YAML rather than JSON-like, while existing JSON and object-example behavior remains correct; add or update coverage for this behavior.