### 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)

int i = 0;
			for (const GDScriptParser::DataType &par_type : parameters_types) {
				valid = valid && par_type == p_function->parameters[i++]->get_datatype();
			}
			if (!valid) {
				
				String parent_signature = function_name.operator String() + "(";
				int j = 0;
				for (const GDScriptParser::DataType &par_type : parameters_types) {
					if (j > 0) {
						parent_signature += ", ";
					}
					String parameter = par_type.to_string();
					if (parameter == "null") {
						parameter = "Variant";
					}
					parent_signature += parameter;
					if (j == parameters_types.size() - default_par_count) {
						parent_signature += " = default";
					}
					j++;
				}
				parent_signature += ") -> ";
				const String return_type = parent_return_type.is_hard_type() ? parent_return_type.to_string() : "Variant";
				if (return_type == "null") {
					parent_signature += "void";
				} else {
					parent_signature += return_type;
				}
				push_error(vformat(R"(The function signature doesn't match the parent. Parent signature is "%s".)", parent_signature), p_function);