### Godot version

v4.0.beta17.official [c40020513]

### System information

Apple M1 Max - macOS Ventura 13.1 (22C65)

### Issue description

I am getting an error due to functions no longer returning the correct typed array, when the function concatenates arrays and returns it.

In other words, the following fails:

```
func add_arrays() -> Array[ClassA]:
	var array_1: Array[ClassA] = []
	var array_2: Array[ClassA] = []
	return array_1 + array_2
```

<img width="864" alt="Screenshot 2023-02-02 at 1 02 53 PM" src="https://user-images.githubusercontent.com/905216/216320503-475bf4a1-353e-455c-87d5-69d036db706c.png">

I'm assuming when concatenating, the typing changes to a generic `Array` now? Just a guess. 

### Steps to reproduce

N/A

### Minimal reproduction project

[Godot Crash Project.zip](https://github.com/godotengine/godot/files/10568780/Godot.Crash.Project.zip)

bool has_valid_setter = false;
				if (member.variable->getter_pointer != nullptr) {
					if (p_class->has_function(member.variable->getter_pointer->name)) {
						getter_function = p_class->get_member(member.variable->getter_pointer->name).function;
					}
					if (getter_function == nullptr) {
						push_error(vformat(R"(Getter "%s" not found.)", member.variable->getter_pointer->name), member.variable);
					} else {
						GDScriptParser::DataType return_datatype = getter_function->datatype;
						if (getter_function->return_type != nullptr) {
							return_datatype = getter_function->return_type->datatype;
							return_datatype.is_meta_type = false;
						}
						if (getter_function->parameters.size() != 0 || return_datatype.has_no_type()) {
							push_error(vformat(R"(Function "%s" cannot be used as getter because of its signature.)", getter_function->identifier->name), member.variable);
						} else if (!is_type_compatible(member.variable->datatype, return_datatype, true)) {
							push_error(vformat(R"(Function with return type "%s" cannot be used as getter for a property of type "%s".)", return_datatype.to_string(), member.variable->datatype.to_string()), member.variable);
						} else {
							has_valid_getter = true;
#ifdef DEBUG_ENABLED
							if (member.variable->datatype.builtin_type == Variant::INT && return_datatype.builtin_type == Variant::FLOAT) {
								parser->push_warning(member.variable, GDScriptWarning::NARROWING_CONVERSION);
							}
#endif
						}
					}
				}
				if (member.variable->setter_pointer != nullptr) {
					if (p_class->has_function(member.variable->setter_pointer->name)) {
						setter_function = p_class->get_member(member.variable->setter_pointer->name).function;