aria-haspopup use requires the use of an ARIA menu, listbox, tree, grid or dialog (see https://www.w3.org/TR/wai-aria-1.1/#aria-haspopup)
in our use (as generic disclosure widgets), it's incorrect and sets up the wrong assumption/behavior from assistive technologies.
in future, we likely want to change our dropdowns to essentially be like a dialog - move focus to it when opened, possibly make it modal so focus is maintained inside it and the rest of the page
is hidden/inert.
but for now, removing the incorrect attribute is probably the quickest, most immediate fix.
Closes #28295 (closed)