Menu bar receives keyboard focus during Tab navigation on Windows and Linux

In desktop apps on Windows and Linux, pressing Tab to move keyboard focus between window controls stops on the menu bar: focus lands on the first menu (for example File), and only the next Tab press moves on to the following control. Menu bars on these platforms are conventionally not part of the Tab order; they are reached with Alt or F10 instead. The unexpected stop makes keyboard navigation slower, and there is no property on MenuBar that excludes it from the Tab order. macOS is not affected because it uses the native menu bar.