[playground] Weird behavior with empty input POST requests

[slinkydeveloper]

I'm still trying to assess whether this is actually a bug of the spec generator or the ui, but so far i'm inclined to say there's something off in the UI, as I don't see the same issue with other OpenAPI UI tools.

Essentially the problem is that I have an operation that is POST but has no request body (that's simply our contract sometimes with some requests/responses):
look in this spec for Counter get. This is what gets rendered:

It adds the content-type, which is definitely incorrect, as it's not in the spec, and requests will fail.

[nikrooz]

This is caused by a bug in Stoplight Elements, created an issue stoplightio/elements#2734