### 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
if (it != drop_mode_over) {
						drop_mode_over = it;
						queue_redraw();
					}
					if (it && section != drop_mode_section) {
						drop_mode_section = section;
						queue_redraw();
					}
				}
				cache.hover_item = it;
				cache.hover_cell = col;
				if (it != old_it || col != old_col) {
					if (old_it && old_col >= old_it->cells.size()) {
						
						queue_redraw();
					} else {
						
						bool was_over_button = old_it && old_it->cells[old_col].custom_button;
						bool is_over_button = it && it->cells[col].custom_button;
						if (was_over_button || is_over_button) {
							queue_redraw();
						}
					}
				}
			}
		}
		
		if (cache.hover_type != old_hover || cache.hover_index != old_index) {
			queue_redraw();
		}