Error to console when handling enter on a label in a flyout

[microbit-matt-hillsdon]

If you add content of kind=label to a toolbox category then the keyboard navigation will visit it and pressing enter on it will cause an error on the console.

bundle.js:2 Uncaught Error: No callback function found for flyout button.
    at Ht.triggerButtonCallback (bundle.js:2:1888927)
    at Object.callback (bundle.js:2:1899298)
    at Fp.onKeyDown (bundle.js:2:1476389)
    at ai (bundle.js:2:1142398)
    at HTMLDocument.s (bundle.js:2:1068151)

There's an example label in the subcategory on this deployment.

I think the typescript type might be missing the kind=label case.

MakeCode uses labels as headings and subheadings in its toolbox flyouts.

[cpcallen]

Hi @microbit-matt-hillsdon. It turns out (and I only learned this very recently) that toolbox labels are actually buttons, which is why there's no type for the kind=label case.

It definitely shouldn't be throwing, though!