### 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)


if (found != nullptr) {
						err = resolve_class_inheritance(found, p_source);
					}
				}
				if (err || found == nullptr) {
					push_error(vformat(R"(Could not resolve script "%s".)", script_path), p_source);
					GDScriptParser::DataType error_type;
					error_type.kind = GDScriptParser::DataType::VARIANT;
					return error_type;
				}
				result.kind = GDScriptParser::DataType::CLASS;
				result.native_type = found->get_datatype().native_type;
				result.class_type = found;
				result.script_path = ref->get_parser()->script_path;
			} else {
				result.kind = GDScriptParser::DataType::SCRIPT;
				result.native_type = scr->get_instance_base_type();
				result.script_path = scr->get_path();
			}
			result.script_type = scr;
		} else {
			result.kind = GDScriptParser::DataType::NATIVE;
			if (result.native_type == GDScriptNativeClass::get_class_static()) {
				result.is_meta_type = true;
			}
		}
	}
	return result;
}
GDScriptParser::DataType GDScriptAnalyzer::type_from_metatype(const GDScriptParser::DataType &p_meta_type) {