### 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
static int recursion_depth = 0;
	RecursionCheck recursion(&recursion_depth);
	if (unlikely(recursion.check())) {
		ERR_FAIL_V_MSG(false, "Reached recursion limit while trying to guess type.");
	}
	GDScriptParser::DataType base_type = p_base.type;
	bool is_static = base_type.is_meta_type;
	if (is_static && p_method == SNAME("new")) {
		r_type.type = base_type;
		r_type.type.is_meta_type = false;
		r_type.type.is_constant = false;
		return true;
	}
	while (base_type.is_set() && !base_type.is_variant()) {
		switch (base_type.kind) {
			case GDScriptParser::DataType::CLASS:
				if (base_type.class_type->has_function(p_method)) {
					const GDScriptParser::FunctionNode *method = base_type.class_type->get_member(p_method).function;
					if (!is_static || method->is_static) {
						if (method->get_datatype().is_set() && !method->get_datatype().is_variant()) {
							r_type.type = method->get_datatype();
							return true;
						}
						int last_return_line = -1;
						const GDScriptParser::ExpressionNode *last_returned_value = nullptr;
						GDScriptParser::CompletionContext c = p_context;
						c.current_class = base_type.class_type;