### 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
columns.write[p_col].text_buf->clear();
	if (columns[p_col].text_direction == Control::TEXT_DIRECTION_INHERITED) {
		columns.write[p_col].text_buf->set_direction(is_layout_rtl() ? TextServer::DIRECTION_RTL : TextServer::DIRECTION_LTR);
	} else {
		columns.write[p_col].text_buf->set_direction((TextServer::Direction)columns[p_col].text_direction);
	}
	columns.write[p_col].text_buf->add_string(columns[p_col].title, theme_cache.font, theme_cache.font_size, columns[p_col].language);
}
void Tree::update_item_cell(TreeItem *p_item, int p_col) {
	String valtext;
	p_item->cells.write[p_col].text_buf->clear();
	if (p_item->cells[p_col].mode == TreeItem::CELL_MODE_RANGE) {
		if (!p_item->cells[p_col].text.is_empty()) {
			if (!p_item->cells[p_col].editable) {
				return;
			}
			int option = (int)p_item->cells[p_col].val;
			valtext = RTR("(Other)");
			Vector<String> strings = p_item->cells[p_col].text.split(",");
			for (int j = 0; j < strings.size(); j++) {
				int value = j;
				if (!strings[j].get_slicec(':', 1).is_empty()) {
					value = strings[j].get_slicec(':', 1).to_int();
				}
				if (option == value) {
					valtext = strings[j].get_slicec(':', 0);
					break;
				}
			}
		} else {