### Godot version

4.1.1

### System information

linux

### Issue description

![image](https://github.com/godotengine/godot-proposals/assets/71937306/04dcf0e9-1c0d-4a7f-8ca9-827dd281253a)

![image](https://github.com/godotengine/godot-proposals/assets/71937306/aa70e31e-0486-455a-b8b4-7e589ec7b754)

notice how the first option in the list is never aligned with the button that spawned it.

### Steps to reproduce

right click in the FileSystem dock and hover over the `Create New →` option.

### Minimal reproduction project

editor
BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, PopupMenu, h_separation);
	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, PopupMenu, indent);
	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, PopupMenu, item_start_padding);
	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, PopupMenu, item_end_padding);
	BIND_THEME_ITEM(Theme::DATA_TYPE_CONSTANT, PopupMenu, icon_max_width);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, checked);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, checked_disabled);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, unchecked);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, unchecked_disabled);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, radio_checked);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, radio_checked_disabled);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, radio_unchecked);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, radio_unchecked_disabled);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, submenu);
	BIND_THEME_ITEM(Theme::DATA_TYPE_ICON, PopupMenu, submenu_mirrored);
	BIND_THEME_ITEM(Theme::DATA_TYPE_FONT, PopupMenu, font);
	BIND_THEME_ITEM(Theme::DATA_TYPE_FONT_SIZE, PopupMenu, font_size);
	BIND_THEME_ITEM(Theme::DATA_TYPE_FONT, PopupMenu, font_separator);
	BIND_THEME_ITEM(Theme::DATA_TYPE_FONT_SIZE, PopupMenu, font_separator_size);
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_color);
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_hover_color);
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_disabled_color);
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_accelerator_color);
	BIND_THEME_ITEM_CUSTOM(Theme::DATA_TYPE_CONSTANT, PopupMenu, font_outline_size, "outline_size");
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_outline_color);
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_separator_color);
	BIND_THEME_ITEM_CUSTOM(Theme::DATA_TYPE_CONSTANT, PopupMenu, font_separator_outline_size, "separator_outline_size");
	BIND_THEME_ITEM(Theme::DATA_TYPE_COLOR, PopupMenu, font_separator_outline_color);
}
void PopupMenu::popup(const Rect2i &p_bounds) {