### Godot version

4.0 rc1

### System information

Windows 11, GTX 1080Ti, Vulkan

### Issue description

Automplete can't find any variables and methods on custom classes when the nodes are loaded with `@onready`:

simple_rotate.gd:
```gdscript
extends Node2D
class_name SimpleRotate

@export var shouldRotate : bool = true
```

machine.gd:
```gdscript
@onready var wheel1 : SimpleRotate = $Wheel

func start_motor():
	wheel1.sho... # Doesn't autocomplete, it can't find shouldRotate 
```

If I add another cast like below, autocomplete does work:
machine.gd:
```gdscript
@onready var wheel1 : SimpleRotate = $Wheel as SimpleRotate

func start_motor():
	wheel1.shouldRotate = true # Autocomplete works
```

To make things even weirder, it does work if I make Wheel into a unique name and access it using %:
machine.gd:
```gdscript
@onready var wheel1 : SimpleRotate = $"%Wheel"

func start_motor():
	wheel1.shouldRotate = true # Autocomplete works
```


### Steps to reproduce

- Create a script with a class_name
- Add that script to a node
- Create another script referencing the node with the type of the script
- Try to let automcomplete find any methods or variables on the script with the class_name
- Notice that it fails

### Minimal reproduction project

N/A
if (p_context.type != GDScriptParser::COMPLETION_SUPER_METHOD) {
						r_type.type = p_context.current_class->get_datatype();
					} else {
						r_type.type = p_context.current_class->base_type;
					}
					found = true;
				}
			} break;
			case GDScriptParser::Node::IDENTIFIER: {
				const GDScriptParser::IdentifierNode *id = static_cast<const GDScriptParser::IdentifierNode *>(p_expression);
				found = _guess_identifier_type(p_context, id, r_type);
			} break;
			case GDScriptParser::Node::DICTIONARY: {
				
				const GDScriptParser::DictionaryNode *dn = static_cast<const GDScriptParser::DictionaryNode *>(p_expression);
				Dictionary d;
				bool full = true;
				for (int i = 0; i < dn->elements.size(); i++) {
					GDScriptCompletionIdentifier key;
					if (_guess_expression_type(p_context, dn->elements[i].key, key)) {
						if (!key.type.is_constant) {
							full = false;
							break;
						}
						GDScriptCompletionIdentifier value;
						if (_guess_expression_type(p_context, dn->elements[i].value, value)) {
							if (!value.type.is_constant) {
								full = false;
								break;
							}