### 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 (p_item && !p_item->is_visible()) {
		
		return 0;
	}
	int item_h = compute_item_height(p_item) + theme_cache.v_separation;
	bool skip = (p_item == root && hide_root);
	if (!skip && p_pos.y < item_h) {
		
		if (range_click_timer->get_time_left() > 0 && p_item != range_item_last) {
			return -1;
		}
		if (!p_item->disable_folding && !hide_folding && p_item->first_child && (p_pos.x >= x_ofs && p_pos.x < (x_ofs + theme_cache.item_margin))) {
			if (enable_recursive_folding && p_mod->is_shift_pressed()) {
				p_item->set_collapsed_recursive(!p_item->is_collapsed());
			} else {
				p_item->set_collapsed(!p_item->is_collapsed());
			}
			return -1;
		}
		int x = p_pos.x;
		
		int col = -1;
		int col_ofs = 0;
		int col_width = 0;
		int limit_w = x_limit;
		for (int i = 0; i < columns.size(); i++) {
			col_width = get_column_width(i);