### 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)


resolve_class_body(p_class);
	if (p_recursive) {
		for (int i = 0; i < p_class->members.size(); i++) {
			GDScriptParser::ClassNode::Member member = p_class->members[i];
			if (member.type == GDScriptParser::ClassNode::Member::CLASS) {
				resolve_class_body(member.m_class, true);
			}
		}
	}
}
void GDScriptAnalyzer::resolve_node(GDScriptParser::Node *p_node, bool p_is_root) {