### 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
if (current.get_identifier() == "get" || current.get_identifier() == "set") {
						return parse_property(variable, false);
					}
				}
			}
			
			variable->datatype_specifier = parse_type();
		}
	}
	if (match(GDScriptTokenizer::Token::EQUAL)) {
		
		variable->initializer = parse_expression(false);
		if (variable->initializer == nullptr) {
			push_error(R"(Expected expression for variable initial value after "=".)");
		}
		variable->assignments++;
	}
	if (p_allow_property && match(GDScriptTokenizer::Token::COLON)) {
		if (match(GDScriptTokenizer::Token::NEWLINE)) {
			return parse_property(variable, true);
		} else {
			return parse_property(variable, false);
		}
	}
	complete_extents(variable);
	end_statement("variable declaration");
	return variable;
}
GDScriptParser::VariableNode *GDScriptParser::parse_property(VariableNode *p_variable, bool p_need_indent) {