### 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)

p_script->fully_qualified_name = p_class->fqcn;
	p_script->name = p_class->identifier ? p_class->identifier->name : "";
	HashMap<StringName, Ref<GDScript>> old_subclasses;
	if (p_keep_state) {
		old_subclasses = p_script->subclasses;
	}
	p_script->subclasses.clear();
	for (int i = 0; i < p_class->members.size(); i++) {
		if (p_class->members[i].type != GDScriptParser::ClassNode::Member::CLASS) {
			continue;
		}
		const GDScriptParser::ClassNode *inner_class = p_class->members[i].m_class;
		StringName name = inner_class->identifier->name;
		Ref<GDScript> subclass;
		if (old_subclasses.has(name)) {
			subclass = old_subclasses[name];
		} else {
			subclass = GDScriptLanguage::get_singleton()->get_orphan_subclass(inner_class->fqcn);
		}
		if (subclass.is_null()) {
			subclass.instantiate();
		}
		subclass->_owner = p_script;
		subclass->path = p_script->path;
		p_script->subclasses.insert(name, subclass);
		make_scripts(subclass.ptr(), inner_class, p_keep_state);
	}
}
Error GDScriptCompiler::compile(const GDScriptParser *p_parser, GDScript *p_script, bool p_keep_state) {