### 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
Size2 size = get_size();
	int tbh;
	if (show_column_titles) {
		tbh = _get_title_button_height();
	} else {
		tbh = 0;
	}
	Size2 hmin = h_scroll->get_combined_minimum_size();
	Size2 vmin = v_scroll->get_combined_minimum_size();
	v_scroll->set_begin(Point2(size.width - vmin.width, theme_cache.panel_style->get_margin(SIDE_TOP)));
	v_scroll->set_end(Point2(size.width, size.height - theme_cache.panel_style->get_margin(SIDE_TOP) - theme_cache.panel_style->get_margin(SIDE_BOTTOM)));
	h_scroll->set_begin(Point2(0, size.height - hmin.height));
	h_scroll->set_end(Point2(size.width - vmin.width, size.height));
	Size2 internal_min_size = get_internal_min_size();
	bool display_vscroll = internal_min_size.height + theme_cache.panel_style->get_margin(SIDE_TOP) > size.height;
	bool display_hscroll = internal_min_size.width + theme_cache.panel_style->get_margin(SIDE_LEFT) > size.width;
	for (int i = 0; i < 2; i++) {
		
		if (display_hscroll) {
			display_vscroll = internal_min_size.height + theme_cache.panel_style->get_margin(SIDE_TOP) + hmin.height > size.height;
		}
		if (display_vscroll) {
			display_hscroll = internal_min_size.width + theme_cache.panel_style->get_margin(SIDE_LEFT) + vmin.width > size.width;
		}
	}