### 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
value_editor->set_step(c.step);
			value_editor->set_value(c.val);
			value_editor->set_exp_ratio(c.expr);
			updating_value_editor = false;
		} else {
			value_editor->hide();
		}
		popup_editor->set_position(popup_rect.position);
		popup_editor->set_size(popup_rect.size);
		popup_editor->popup();
		popup_editor->child_controls_changed();
		text_editor->grab_focus();
		return true;
	}
	return false;
}
bool Tree::is_editing() {
	return popup_editor->is_visible();
}
Size2 Tree::get_internal_min_size() const {
	Size2i size = theme_cache.panel_style->get_offset();
	if (root) {
		size.height += get_item_height(root);
	}
	for (int i = 0; i < columns.size(); i++) {
		size.width += get_column_minimum_width(i);
	}
	return size;
}
void Tree::update_scrollbars() {