### 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 (base_class->fqcn == p_class->fqcn) {
			push_error("Cyclic inheritance.", p_class);
			return ERR_PARSE_ERROR;
		}
		base_class = base_class->base_type.class_type;
	}
	p_class->base_type = result;
	class_type.native_type = result.native_type;
	p_class->set_datatype(class_type);
	parser->current_class = previous_class;
	return OK;
}
Error GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode *p_class, bool p_recursive) {
	Error err = resolve_class_inheritance(p_class);
	if (err) {
		return err;
	}
	if (p_recursive) {
		for (int i = 0; i < p_class->members.size(); i++) {
			if (p_class->members[i].type == GDScriptParser::ClassNode::Member::CLASS) {
				err = resolve_class_inheritance(p_class->members[i].m_class, true);
				if (err) {
					return err;
				}
			}
		}
	}
	return OK;
}
GDScriptParser::DataType GDScriptAnalyzer::resolve_datatype(GDScriptParser::TypeNode *p_type) {