This seems to have broken in beta 99. The "X" button is getting focus.

beta 97
Sets focus on the component. By default, tries to focus on focusable content. If there is none, it will focus on the close button. To focus on the close button, use the close-button focus ID.
let button = document.createElement('calcite-button');
button.setAttribute('slot', 'secondary');
button.innerHTML = 'Cancel';
??? not working
button.setFocus('close-button');