### 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
while (check(GDScriptTokenizer::Token::DEDENT) || check(GDScriptTokenizer::Token::INDENT) || check(GDScriptTokenizer::Token::NEWLINE)) {
			current = tokenizer.scan(); 
		}
		tokenizer.pop_expression_indented_block();
	}
	current_function = previous_function;
	in_lambda = previous_in_lambda;
	lambda->function = function;
	
	can_break = could_break;
	can_continue = could_continue;
	return lambda;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_type_test(ExpressionNode *p_previous_operand, bool p_can_assign) {
	TypeTestNode *type_test = alloc_node<TypeTestNode>();
	reset_extents(type_test, p_previous_operand);
	update_extents(type_test);
	type_test->operand = p_previous_operand;
	type_test->test_type = parse_type();
	complete_extents(type_test);
	if (type_test->test_type == nullptr) {
		push_error(R"(Expected type specifier after "is".)");
	}
	return type_test;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_yield(ExpressionNode *p_previous_operand, bool p_can_assign) {
	push_error(R"("yield" was removed in Godot 4.0. Use "await" instead.)");
	return nullptr;
}
GDScriptParser::ExpressionNode *GDScriptParser::parse_invalid_token(ExpressionNode *p_previous_operand, bool p_can_assign) {