### 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)


StringName function_name = p_call->function_name;
		Variant::Type builtin_type = GDScriptParser::get_builtin_type(function_name);
		if (builtin_type < Variant::VARIANT_MAX) {
			
			call_type.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
			call_type.kind = GDScriptParser::DataType::BUILTIN;
			call_type.builtin_type = builtin_type;
			if (builtin_type == Variant::OBJECT) {
				call_type.kind = GDScriptParser::DataType::NATIVE;
				call_type.native_type = function_name; 
			}
			bool safe_to_fold = true;
			switch (builtin_type) {
				
				
				case Variant::OBJECT:
				case Variant::DICTIONARY:
				case Variant::ARRAY:
				case Variant::PACKED_BYTE_ARRAY:
				case Variant::PACKED_INT32_ARRAY:
				case Variant::PACKED_INT64_ARRAY:
				case Variant::PACKED_FLOAT32_ARRAY:
				case Variant::PACKED_FLOAT64_ARRAY:
				case Variant::PACKED_STRING_ARRAY:
				case Variant::PACKED_VECTOR2_ARRAY:
				case Variant::PACKED_VECTOR3_ARRAY:
				case Variant::PACKED_COLOR_ARRAY:
					safe_to_fold = false;
					break;
				default: