### 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 (collapsed == p_collapsed || !tree) {
		return;
	}
	collapsed = p_collapsed;
	TreeItem *ci = tree->selected_item;
	if (ci) {
		while (ci && ci != this) {
			ci = ci->parent;
		}
		if (ci) { 
			if (tree->select_mode == Tree::SELECT_MULTI) {
				tree->selected_item = this;
				emit_signal(SNAME("cell_selected"));
			} else {
				select(tree->selected_col);
			}
			tree->queue_redraw();
		}
	}
	_changed_notify();
	tree->emit_signal(SNAME("item_collapsed"), this);
}
bool TreeItem::is_collapsed() {
	return collapsed;
}
void TreeItem::set_collapsed_recursive(bool p_collapsed) {