### 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
ClassDB::bind_method(D_METHOD("is_root_hidden"), &Tree::is_root_hidden);
	ClassDB::bind_method(D_METHOD("get_next_selected", "from"), &Tree::get_next_selected);
	ClassDB::bind_method(D_METHOD("get_selected"), &Tree::get_selected);
	ClassDB::bind_method(D_METHOD("set_selected", "item", "column"), &Tree::set_selected);
	ClassDB::bind_method(D_METHOD("get_selected_column"), &Tree::get_selected_column);
	ClassDB::bind_method(D_METHOD("get_pressed_button"), &Tree::get_pressed_button);
	ClassDB::bind_method(D_METHOD("set_select_mode", "mode"), &Tree::set_select_mode);
	ClassDB::bind_method(D_METHOD("get_select_mode"), &Tree::get_select_mode);
	ClassDB::bind_method(D_METHOD("set_columns", "amount"), &Tree::set_columns);
	ClassDB::bind_method(D_METHOD("get_columns"), &Tree::get_columns);
	ClassDB::bind_method(D_METHOD("get_edited"), &Tree::get_edited);
	ClassDB::bind_method(D_METHOD("get_edited_column"), &Tree::get_edited_column);
	ClassDB::bind_method(D_METHOD("edit_selected"), &Tree::edit_selected);
	ClassDB::bind_method(D_METHOD("get_custom_popup_rect"), &Tree::get_custom_popup_rect);
	ClassDB::bind_method(D_METHOD("get_item_area_rect", "item", "column", "button_index"), &Tree::get_item_rect, DEFVAL(-1), DEFVAL(-1));
	ClassDB::bind_method(D_METHOD("get_item_at_position", "position"), &Tree::get_item_at_position);
	ClassDB::bind_method(D_METHOD("get_column_at_position", "position"), &Tree::get_column_at_position);
	ClassDB::bind_method(D_METHOD("get_drop_section_at_position", "position"), &Tree::get_drop_section_at_position);
	ClassDB::bind_method(D_METHOD("get_button_id_at_position", "position"), &Tree::get_button_id_at_position);
	ClassDB::bind_method(D_METHOD("ensure_cursor_is_visible"), &Tree::ensure_cursor_is_visible);
	ClassDB::bind_method(D_METHOD("set_column_titles_visible", "visible"), &Tree::set_column_titles_visible);
	ClassDB::bind_method(D_METHOD("are_column_titles_visible"), &Tree::are_column_titles_visible);
	ClassDB::bind_method(D_METHOD("set_column_title", "column", "title"), &Tree::set_column_title);
	ClassDB::bind_method(D_METHOD("get_column_title", "column"), &Tree::get_column_title);
	ClassDB::bind_method(D_METHOD("set_column_title_direction", "column", "direction"), &Tree::set_column_title_direction);
	ClassDB::bind_method(D_METHOD("get_column_title_direction", "column"), &Tree::get_column_title_direction);
	ClassDB::bind_method(D_METHOD("set_column_title_language", "column", "language"), &Tree::set_column_title_language);
	ClassDB::bind_method(D_METHOD("get_column_title_language", "column"), &Tree::get_column_title_language);
	ClassDB::bind_method(D_METHOD("get_scroll"), &Tree::get_scroll);
	ClassDB::bind_method(D_METHOD("scroll_to_item", "item", "center_on_item"), &Tree::scroll_to_item, DEFVAL(false));