### Godot version

ef025711a

### System information

ArchLinux x11

### Issue description

Accessing a scene unique node like this:
```gdscript
class_name Class extends Node
static func get_label() -> Label:
	return %label
```
and then accessing that class later:
```gdscript
func _ready() -> void:
	Main.get_label().text = "hello world"
```
causes a strange error when in the editor, and a normal error when run directly.
![image](https://user-images.githubusercontent.com/70787919/229785642-6aad4e31-6bd9-4eb5-bee4-7445b48a99bb.png)
```c++
ERROR: Node not found: "%label" (relative to "/root/main").
   at: get_node (scene/main/node.cpp:1364)
```
Instead of returning null.
As opposed to when using `get_node`:
```

SCRIPT ERROR: Cannot call method 'get_node' on a null value.
          at: get_label (res://main.gd:5)
SCRIPT ERROR: Invalid set index 'text' (on base: 'Nil') with value of type 'String'.
          at: _ready (res://control.gd:4)
```

### Steps to reproduce

Run mrp or follow outlined steps

### Minimal reproduction project

[bug.zip](https://github.com/godotengine/godot/files/11148287/bug.zip)

ExpressionNode *grouped = parse_expression(false);
	pop_multiline();
	if (grouped == nullptr) {
		push_error(R"(Expected grouping expression.)");
	} else {
		consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, R"*(Expected closing ")" after grouping expression.)*");
	}
	return grouped;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_attribute(ExpressionNode *p_previous_operand, bool p_can_assign) {
	SubscriptNode *attribute = alloc_node<SubscriptNode>();
	reset_extents(attribute, p_previous_operand);
	update_extents(attribute);
	if (for_completion) {
		bool is_builtin = false;
		if (p_previous_operand && p_previous_operand->type == Node::IDENTIFIER) {
			const IdentifierNode *id = static_cast<const IdentifierNode *>(p_previous_operand);
			Variant::Type builtin_type = get_builtin_type(id->name);
			if (builtin_type < Variant::VARIANT_MAX) {
				make_completion_context(COMPLETION_BUILT_IN_TYPE_CONSTANT_OR_STATIC_METHOD, builtin_type, true);
				is_builtin = true;
			}
		}
		if (!is_builtin) {
			make_completion_context(COMPLETION_ATTRIBUTE, attribute, -1, true);
		}