### Godot version

4.0 RC 3

### System information

Macbook m1

### Issue description

If I normally use:
```
Skeleton2D.new()
```

if works.

If I use:
```
@export_group("Skeleton2D")
...
Skeleton2D.new()
```

I get error: `Invalid call. Nonexistent function 'new' in base 'Nil'.`

### Steps to reproduce

- Run a script where you have `@export_group` with same name as a node class name that you use `.new()` on.

```
extends Node2D
class_name Test

@export_group("Skeleton2D")

# Called when the node enters the scene tree for the first time.
func _ready():
	var skeleton = Skeleton2D.new()


# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	pass
```

### Minimal reproduction project

[BugNew.zip](https://github.com/godotengine/godot/files/10818936/BugNew.zip)

p_script->fully_qualified_name = p_class->fqcn;
	p_script->name = p_class->identifier ? p_class->identifier->name : "";
	HashMap<StringName, Ref<GDScript>> old_subclasses;
	if (p_keep_state) {
		old_subclasses = p_script->subclasses;
	}
	p_script->subclasses.clear();
	for (int i = 0; i < p_class->members.size(); i++) {
		if (p_class->members[i].type != GDScriptParser::ClassNode::Member::CLASS) {
			continue;
		}
		const GDScriptParser::ClassNode *inner_class = p_class->members[i].m_class;
		StringName name = inner_class->identifier->name;
		Ref<GDScript> subclass;
		if (old_subclasses.has(name)) {
			subclass = old_subclasses[name];
		} else {
			subclass = GDScriptLanguage::get_singleton()->get_orphan_subclass(inner_class->fqcn);
		}
		if (subclass.is_null()) {
			subclass.instantiate();
		}
		subclass->_owner = p_script;
		subclass->path = p_script->path;
		p_script->subclasses.insert(name, subclass);
		make_scripts(subclass.ptr(), inner_class, p_keep_state);
	}
}
Error GDScriptCompiler::compile(const GDScriptParser *p_parser, GDScript *p_script, bool p_keep_state) {