### Godot version

4.1.1

### System information

windows 11

### Issue description

When registering a type with class_name and using that class name to declare a variable in code only, autocomplete works as expected anywhere in other nodes/scenes. However, if making a custom scene node that extends a script with the class_name, if that custom scene is instantiated in a different scene, even if the type is specified, it only shows the parent node's functions and not any of the extended functionality. I have made a basic project showing the issue

### Steps to reproduce

I have made a very simple project showing the issue. https://github.com/mmmmmmmmmmmmmmmmmmmdonuts/godot_4_autocomplete_issue essentially, the extended Node scene will only show the custom function when both the type is specified as well as the type afterwards following "as" 
e.g. `@onready var my_class_4: MyClass = $MyClass4 as MyClass`

### Minimal reproduction project

https://github.com/mmmmmmmmmmmmmmmmmmmdonuts/godot_4_autocomplete_issue
for (List<Pair<String, Variant>>::Element *CE = cinfo.front(); CE; CE = CE->next()) {
			if (CE->get().first == E.key) {
				is_script_constant = true;
				break;
			}
		}
		if (is_script_constant) {
			continue;
		}
		const Variant &var = gl_array[E.value];
		if (Object *obj = var) {
			if (Object::cast_to<GDScriptNativeClass>(obj)) {
				continue;
			}
		}
		bool skip = false;
		for (int i = 0; i < CoreConstants::get_global_constant_count(); i++) {
			if (E.key == CoreConstants::get_global_constant_name(i)) {
				skip = true;
				break;
			}
		}
		if (skip) {
			continue;
		}
		p_globals->push_back(E.key);
		p_values->push_back(var);
	}
}
String GDScriptLanguage::debug_parse_stack_level_expression(int p_level, const String &p_expression, int p_max_subitems, int p_max_depth) {