[graphiql-react] Prettify button missing red error class on invalid queries

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Current Behavior

The prettify button used to turn red if it failed to prettify, it doesn't seem to be doing that anymore

### Expected Behavior

If you press the prettify button on an invalid query that cannot prettify, the button should turn red

### Steps To Reproduce

In the swapi or netlify demos, type an incorrect query and press prettify

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The button used to turn red like this but doesn't anymore

### Environment

* GraphiQL Version:
* OS:
* Browser:
* Bundler:
* `react` Version:
* `graphql` Version:

### Anything else?

I think this could be fixed by throwing the errors in the prettifyEditors function, then in the ToolbarButton change the onClick type to onClick: (args?: any) => (any | Promise); and await the onClick