### 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)

if (parsed_classes.has(p_script)) {
		return OK;
	}
	if (parsing_classes.has(p_script)) {
		String class_name = p_class->identifier ? String(p_class->identifier->name) : p_class->fqcn;
		_set_error(vformat(R"(Cyclic class reference for "%s".)", class_name), p_class);
		return ERR_PARSE_ERROR;
	}
	parsing_classes.insert(p_script);
	p_script->clearing = true;
#ifdef TOOLS_ENABLED
	p_script->doc_functions.clear();
	p_script->doc_variables.clear();
	p_script->doc_constants.clear();
	p_script->doc_enums.clear();
	p_script->doc_signals.clear();
	p_script->doc_tutorials.clear();
	p_script->doc_brief_description = p_class->doc_brief_description;
	p_script->doc_description = p_class->doc_description;
	for (int i = 0; i < p_class->doc_tutorials.size(); i++) {
		DocData::TutorialDoc td;
		td.title = p_class->doc_tutorials[i].first;
		td.link = p_class->doc_tutorials[i].second;
		p_script->doc_tutorials.append(td);
	}
#endif
	p_script->native = Ref<GDScriptNativeClass>();
	p_script->base = Ref<GDScript>();