### 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)

} else {
			push_error(vformat(R"(Invalid operands "%s" and "%s" for assignment operator.)", assignee_type.to_string(), assigned_value_type.to_string()), p_assignment);
		}
	} else if (assignee_type.is_hard_type() && !assignee_type.is_variant()) {
		mark_node_unsafe(p_assignment);
		p_assignment->use_conversion_assign = true;
	} else {
		mark_node_unsafe(p_assignment);
		if (assignee_type.is_hard_type() && !assignee_type.is_variant()) {
			p_assignment->use_conversion_assign = true;
		}
	}
	if (p_assignment->assignee->type == GDScriptParser::Node::IDENTIFIER) {
		
		GDScriptParser::IdentifierNode *identifier = static_cast<GDScriptParser::IdentifierNode *>(p_assignment->assignee);
		switch (identifier->source) {
			case GDScriptParser::IdentifierNode::MEMBER_VARIABLE: {
				GDScriptParser::DataType id_type = identifier->variable_source->get_datatype();
				if (!id_type.is_hard_type()) {
					id_type.kind = GDScriptParser::DataType::VARIANT;
					id_type.type_source = GDScriptParser::DataType::UNDETECTED;
					identifier->variable_source->set_datatype(id_type);
				}
			} break;
			case GDScriptParser::IdentifierNode::FUNCTION_PARAMETER: {
				GDScriptParser::DataType id_type = identifier->parameter_source->get_datatype();
				if (!id_type.is_hard_type()) {
					id_type.kind = GDScriptParser::DataType::VARIANT;
					id_type.type_source = GDScriptParser::DataType::UNDETECTED;
					identifier->parameter_source->set_datatype(id_type);