### Godot version

4.1.beta3

### System information

Fedora Workstation 38 - Godot 4.1.beta3 - Vulkan (Forward+)

### Issue description

**This is an issue created by the production team, we're working on it**

Currently, it's impossible to call virtual functions within GDScript.

This currently returns an error:
```gdscript
# a.gd
extends Node

func _process(delta: float) -> void:
	pass
```

```gdscript
# main.gd
extends Node

var my_node: Node = preload("res://a.gd").new()

func _process(delta: float) -> void:
	my_node._process(delta)  # Cannot call virtual function "_process()" because it hasn't been defined.
```

### Steps to reproduce

1. Create a script (`a.gd`) based on `Node` that declares `_process()`;
2. Create a main node;
3. Attach a script to the main node;
4. Initialize a variable with a new `a.gd` instance;
5. Try to run `_process()` on that node;
6. Find out that it returns an error.

### Minimal reproduction project

[virtual_functions.zip (updated)](https://github.com/godotengine/godot/files/11823992/virtual_functions.zip)


GDScriptParser::DataType result;
	result.is_constant = true;
	result.kind = GDScriptParser::DataType::BUILTIN;
	result.builtin_type = p_value.get_type();
	result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT; 
	if (p_value.get_type() == Variant::ARRAY) {
		const Array &array = p_value;
		if (array.get_typed_script()) {
			result.set_container_element_type(type_from_metatype(make_script_meta_type(array.get_typed_script())));
		} else if (array.get_typed_class_name()) {
			result.set_container_element_type(type_from_metatype(make_native_meta_type(array.get_typed_class_name())));
		} else if (array.get_typed_builtin() != Variant::NIL) {
			result.set_container_element_type(type_from_metatype(make_builtin_meta_type((Variant::Type)array.get_typed_builtin())));
		}
	} else if (p_value.get_type() == Variant::OBJECT) {