### 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)

if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected parameter name.)")) {
		return nullptr;
	}
	ParameterNode *parameter = alloc_node<ParameterNode>();
	parameter->identifier = parse_identifier();
	if (match(GDScriptTokenizer::Token::COLON)) {
		if (check((GDScriptTokenizer::Token::EQUAL))) {
			
			parameter->infer_datatype = true;
		} else {
			
			make_completion_context(COMPLETION_TYPE_NAME, parameter);
			parameter->datatype_specifier = parse_type();
		}
	}
	if (match(GDScriptTokenizer::Token::EQUAL)) {
		
		parameter->initializer = parse_expression(false);
	}
	complete_extents(parameter);
	return parameter;
}
GDScriptParser::SignalNode *GDScriptParser::parse_signal(bool p_is_static) {
	SignalNode *signal = alloc_node<SignalNode>();
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected signal name after "signal".)")) {
		complete_extents(signal);
		return nullptr;
	}
	signal->identifier = parse_identifier();
	if (check(GDScriptTokenizer::Token::PARENTHESIS_OPEN)) {