Steps to reproduce: 1. Open an ActionMenu with click (not keyboard). Focus will stay on the anchor. 2. Press ArrowDown to move focus from anchor to first item This also fires page scroll event In docs, https://user-images.githubusercontent.com/6636360/185539825-0ec1bf4a-e307-4d1a-9c3d-84ee9b117a57.mov In memex, https://user-images.githubusercontent.com/1863771/185975424-d5e3bfc0-48ea-436c-b4e4-c24df9f6776c.mov #### Impact: Low, tiny annoyance for users that use both mouse and keyboard in the menu #### Solution: We might need to prevent the scroll event when moving focus for the first time in [useMoveFocusToMenuItem](https://github.com/primer/react/blob/main/src/hooks/useMenuKeyboardNavigation.ts#L86)