### 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
ofs = get_column_width(0);
					continue;
				}
			} else {
				ofs += theme_cache.h_separation;
				w -= theme_cache.h_separation;
			}
			if (p_item->cells[i].expand_right) {
				int plus = 1;
				while (i + plus < columns.size() && !p_item->cells[i + plus].editable && p_item->cells[i + plus].mode == TreeItem::CELL_MODE_STRING && p_item->cells[i + plus].text.is_empty() && p_item->cells[i + plus].icon.is_null()) {
					w += get_column_width(i + plus);
					plus++;
					skip2++;
				}
			}
			if (!rtl && p_item->cells[i].buttons.size()) {
				int button_w = 0;
				for (int j = p_item->cells[i].buttons.size() - 1; j >= 0; j--) {
					Ref<Texture2D> b = p_item->cells[i].buttons[j].texture;
					button_w += b->get_size().width + theme_cache.button_pressed->get_minimum_size().width + theme_cache.button_margin;
				}
				int total_ofs = ofs - theme_cache.offset.x;
				if (total_ofs + w > p_draw_size.width) {
					w = MAX(button_w, p_draw_size.width - total_ofs);
				}
			}
			int bw = 0;
			for (int j = p_item->cells[i].buttons.size() - 1; j >= 0; j--) {
				Ref<Texture2D> b = p_item->cells[i].buttons[j].texture;
				Size2 s = b->get_size() + theme_cache.button_pressed->get_minimum_size();