### 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)

GDScriptParser::DataType class_type;
	class_type.is_constant = true;
	class_type.is_meta_type = true;
	class_type.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
	class_type.kind = GDScriptParser::DataType::CLASS;
	class_type.class_type = p_class;
	class_type.script_path = parser->script_path;
	class_type.builtin_type = Variant::OBJECT;
	p_class->set_datatype(class_type);
	GDScriptParser::DataType result;
	if (!p_class->extends_used) {
		result.type_source = GDScriptParser::DataType::ANNOTATED_INFERRED;
		result.kind = GDScriptParser::DataType::NATIVE;
		result.native_type = SNAME("RefCounted");
	} else {
		result.type_source = GDScriptParser::DataType::ANNOTATED_EXPLICIT;
		GDScriptParser::DataType base;
		int extends_index = 0;
		if (!p_class->extends_path.is_empty()) {
			if (p_class->extends_path.is_relative_path()) {
				p_class->extends_path = class_type.script_path.get_base_dir().path_join(p_class->extends_path).simplify_path();
			}
			Ref<GDScriptParserRef> ext_parser = get_parser_for(p_class->extends_path);
			if (ext_parser.is_null()) {
				push_error(vformat(R"(Could not resolve super class path "%s".)", p_class->extends_path), p_class);
				return ERR_PARSE_ERROR;
			}
			Error err = ext_parser->raise_status(GDScriptParserRef::INHERITANCE_SOLVED);
			if (err != OK) {
				push_error(vformat(R"(Could not resolve super class inheritance from "%s".)", p_class->extends_path), p_class);