YaruPopupMenuButton long press releases without mouse release

[Feichtmeier]

This is a normal material button, only releasing the long press when one releases the mouse key:

Bildschirmaufzeichnung vom 2023-05-31, 10-39-59.webm

This is the popup button which auto releases the press even if one does not release the mouse

Bildschirmaufzeichnung vom 2023-05-31, 10-41-07.webm

https://github.com/ubuntu/yaru_widgets.dart/blob/49061871c8c3f69ff7429be891eaa83ec88b3bd8/lib/src/widgets/yaru_popup_menu_button.dart#L67