### 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
push_error(R"(Expected expression as the function argument.)");
		} else {
			call->arguments.push_back(argument);
			if (argument->type == Node::IDENTIFIER && use_identifier_completion) {
				completion_context.type = COMPLETION_IDENTIFIER;
			}
		}
		ct = COMPLETION_CALL_ARGUMENTS;
	} while (match(GDScriptTokenizer::Token::COMMA));
	pop_completion_call();
	pop_multiline();
	consume(GDScriptTokenizer::Token::PARENTHESIS_CLOSE, R"*(Expected closing ")" after call arguments.)*");
	complete_extents(call);
	return call;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_get_node(ExpressionNode *p_previous_operand, bool p_can_assign) {
	if (!current.is_node_name() && !check(GDScriptTokenizer::Token::LITERAL) && !check(GDScriptTokenizer::Token::SLASH) && !check(GDScriptTokenizer::Token::PERCENT)) {
		push_error(vformat(R"(Expected node path as string or identifier after "%s".)", previous.get_name()));
		return nullptr;
	}
	if (check(GDScriptTokenizer::Token::LITERAL)) {
		if (current.literal.get_type() != Variant::STRING) {
			push_error(vformat(R"(Expected node path as string or identifier after "%s".)", previous.get_name()));
			return nullptr;
		}
	}
	GetNodeNode *get_node = alloc_node<GetNodeNode>();
	
	
	enum PathState {