### 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
}
	attribute->base = p_previous_operand;
	if (current.is_node_name()) {
		current.type = GDScriptTokenizer::Token::IDENTIFIER;
	}
	if (!consume(GDScriptTokenizer::Token::IDENTIFIER, R"(Expected identifier after "." for attribute access.)")) {
		complete_extents(attribute);
		return attribute;
	}
	attribute->is_attribute = true;
	attribute->attribute = parse_identifier();
	complete_extents(attribute);
	return attribute;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_subscript(ExpressionNode *p_previous_operand, bool p_can_assign) {
	SubscriptNode *subscript = alloc_node<SubscriptNode>();
	reset_extents(subscript, p_previous_operand);
	update_extents(subscript);
	make_completion_context(COMPLETION_SUBSCRIPT, subscript);
	subscript->base = p_previous_operand;
	subscript->index = parse_expression(false);
	if (subscript->index == nullptr) {
		push_error(R"(Expected expression after "[".)");
	}
	pop_multiline();
	consume(GDScriptTokenizer::Token::BRACKET_CLOSE, R"(Expected "]" after subscription index.)");
	complete_extents(subscript);
	return subscript;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_cast(ExpressionNode *p_previous_operand, bool p_can_assign) {