### Godot version

v4.0.3.stable.official [5222a99f5]
Master [6101240231600c871f5c5473872532c68ea3268c] (confirmed by https://github.com/godotengine/godot/issues/77666#issuecomment-1568952502)

### System information

Window 10

### Issue description

References are not unreferenced at the end of `if` scopes.

### Steps to reproduce

Copy, paste and run the snippet below, check the results:

```gdscript
extends Node


func _ready() -> void:
  var ref := RefCounted.new()
  var ref_count : int

  # OK
  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # OK
  if true:
    var temp := ref
    temp = null

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)

  # FAIL
  if true:
    var temp := ref

  ref_count = ref.get_reference_count()
  print('Expected: 1, Result: %d' % ref_count)
```

Output example:

```
Expected: 1, Result: 1
Expected: 1, Result: 1
Expected: 1, Result: 2
```

### Minimal reproduction project

N/A
GDScriptTokenizer::Token::Type invalid = previous.type;
	switch (invalid) {
		case GDScriptTokenizer::Token::QUESTION_MARK:
			push_error(R"(Unexpected "?" in source. If you want a ternary operator, use "truthy_value if true_condition else falsy_value".)");
			break;
		default:
			return nullptr; 
	}
	
	return p_previous_operand;
}
GDScriptParser::TypeNode *GDScriptParser::parse_type(bool p_allow_void) {
	TypeNode *type = alloc_node<TypeNode>();
	make_completion_context(p_allow_void ? COMPLETION_TYPE_NAME_OR_VOID : COMPLETION_TYPE_NAME, type);
	if (!match(GDScriptTokenizer::Token::IDENTIFIER)) {
		if (match(GDScriptTokenizer::Token::VOID)) {
			if (p_allow_void) {
				complete_extents(type);
				TypeNode *void_type = type;
				return void_type;
			} else {
				push_error(R"("void" is only allowed for a function return type.)");
			}
		}
		
		complete_extents(type);
		return nullptr;
	}
	IdentifierNode *type_element = parse_identifier();