### Godot version

4.0 beta 10

### System information

Windows 11 Vulkan

### Issue description

Looked through the issues list, but couldn't find something like this, sorry in advance if this has already been reported.

There is a few cases (in the pictures below) where list of Actions in Input Map may not always show a scrollbar even if the actions list overflows (I imagine this could also happen for the widget that Input Map uses).

![image](https://user-images.githubusercontent.com/39958198/210003566-cf60dbaf-921f-485b-b0a9-51ffc28d0244.png)

![New Bitmap image](https://user-images.githubusercontent.com/39958198/210004079-8eb2e6a1-0cf5-4a7c-8905-a4e3cfd0ec5d.png)

![image](https://user-images.githubusercontent.com/39958198/210004165-a6b6790b-248a-4f68-b4d0-b44b25afdf4f.png)

![image](https://user-images.githubusercontent.com/39958198/210004537-aca52194-a464-48b9-b818-24782706de45.png)


### Steps to reproduce

The pictures are clearer than anything I could write here: "a picture is worth 1000 words"

### Minimal reproduction project

N/A
}
			case TreeItem::CELL_MODE_STRING:
			case TreeItem::CELL_MODE_CUSTOM:
			case TreeItem::CELL_MODE_ICON: {
				Ref<Texture2D> icon = p_item->cells[i].icon;
				if (!icon.is_null()) {
					Size2i s = p_item->cells[i].get_icon_size();
					if (p_item->cells[i].icon_max_w > 0 && s.width > p_item->cells[i].icon_max_w) {
						s.height = s.height * p_item->cells[i].icon_max_w / s.width;
					}
					if (s.height > height) {
						height = s.height;
					}
				}
				if (p_item->cells[i].mode == TreeItem::CELL_MODE_CUSTOM && p_item->cells[i].custom_button) {
					height += theme_cache.custom_button->get_minimum_size().height;
				}
			} break;
			default: {
			}
		}
	}
	int item_min_height = p_item->get_custom_minimum_height();
	if (height < item_min_height) {
		height = item_min_height;
	}
	height += theme_cache.v_separation;
	return height;
}
int Tree::get_item_height(TreeItem *p_item) const {