Tests the signed exchange information are available when the prefetch failed.
* http://127.0.0.1:8000/loading/sxg/resources/sxg-invalid-validity-url.sxg
failed: true
statusCode: 200
resourceType: other
SignedExchangeInfo
Error: {"message":"Validity URL must be same-origin with request URL."}
Error: {"message":"Failed to parse SignedExchange header."}