### Godot version

4.0 Beta10

### System information

Windows 10, Vulkan, GTX1060

### Issue description

`PropertyTweener`'s methods' return value are not discarded and effect the unary operator at next line.

In Editor:
![in_editor](https://user-images.githubusercontent.com/61624558/210715100-04bdf283-7954-4be3-94ca-338987b24c5b.png)


In cpp:
![in_cpp](https://user-images.githubusercontent.com/61624558/210715127-519f6d54-fc15-468f-9aca-ba7d387a5a7b.png)


### Steps to reproduce

Just run the Minimal reproduction project.

### Minimal reproduction project

[Bug Report.zip](https://github.com/godotengine/godot/files/10349829/Bug.Report.zip)

}
				result = ref->get_parser()->head->get_datatype();
			} else {
				result.kind = GDScriptParser::DataType::SCRIPT;
				result.script_type = ResourceLoader::load(path, "Script");
				result.native_type = result.script_type->get_instance_base_type();
				result.script_path = path;
				result.is_constant = true;
				result.is_meta_type = false;
			}
		}
	} else if (ProjectSettings::get_singleton()->has_autoload(first) && ProjectSettings::get_singleton()->get_autoload(first).is_singleton) {
		const ProjectSettings::AutoloadInfo &autoload = ProjectSettings::get_singleton()->get_autoload(first);
		Ref<GDScriptParserRef> ref = get_parser_for(autoload.path);
		if (ref->raise_status(GDScriptParserRef::INHERITANCE_SOLVED) != OK) {
			push_error(vformat(R"(Could not parse singleton "%s" from "%s".)", first, autoload.path), p_type);
			return bad_type;
		}
		result = ref->get_parser()->head->get_datatype();
	} else if (ClassDB::has_enum(parser->current_class->base_type.native_type, first)) {
		
		result = make_native_enum_type(parser->current_class->base_type.native_type, first);
	} else {
		
		List<GDScriptParser::ClassNode *> script_classes;
		get_class_node_current_scope_classes(parser->current_class, &script_classes);
		for (GDScriptParser::ClassNode *script_class : script_classes) {
			if (script_class->identifier && script_class->identifier->name == first) {
				result = script_class->get_datatype();
				break;