### 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 (display_vscroll) {
		v_scroll->show();
		v_scroll->set_max(internal_min_size.height);
		v_scroll->set_page(size.height - hmin.height - tbh);
		theme_cache.offset.y = v_scroll->get_value();
	} else {
		v_scroll->hide();
		theme_cache.offset.y = 0;
	}
	if (display_hscroll) {
		h_scroll->show();
		h_scroll->set_max(internal_min_size.width);
		h_scroll->set_page(size.width - vmin.width);
		theme_cache.offset.x = h_scroll->get_value();
	} else {
		h_scroll->hide();
		theme_cache.offset.x = 0;
	}
}
int Tree::_get_title_button_height() const {
	ERR_FAIL_COND_V(theme_cache.font.is_null() || theme_cache.title_button.is_null(), 0);
	int h = 0;
	if (show_column_titles) {
		for (int i = 0; i < columns.size(); i++) {
			h = MAX(h, columns[i].text_buf->get_size().y + theme_cache.title_button->get_minimum_size().height);
		}
	}
	return h;
}
void Tree::_notification(int p_what) {