### 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
SubscriptNode *attribute = static_cast<SubscriptNode *>(call->callee);
			if (attribute->is_attribute) {
				if (attribute->attribute) {
					call->function_name = attribute->attribute->name;
				}
				make_completion_context(COMPLETION_ATTRIBUTE_METHOD, call->callee);
			} else {
				
				push_error(R"*(Cannot call on an expression. Use ".call()" if it's a Callable.)*");
			}
		} else {
			push_error(R"*(Cannot call on an expression. Use ".call()" if it's a Callable.)*");
		}
	}
	
	CompletionType ct = COMPLETION_CALL_ARGUMENTS;
	if (call->function_name == SNAME("load")) {
		ct = COMPLETION_RESOURCE_PATH;
	}
	push_completion_call(call);
	int argument_index = 0;
	do {
		make_completion_context(ct, call, argument_index++, true);
		if (check(GDScriptTokenizer::Token::PARENTHESIS_CLOSE)) {
			
			break;
		}
		bool use_identifier_completion = current.cursor_place == GDScriptTokenizer::CURSOR_END || current.cursor_place == GDScriptTokenizer::CURSOR_MIDDLE;
		ExpressionNode *argument = parse_expression(false);
		if (argument == nullptr) {