### 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)

break;
							
							case Variant::RID:
							case Variant::BOOL:
							case Variant::CALLABLE:
							case Variant::FLOAT:
							case Variant::INT:
							case Variant::NIL:
							case Variant::NODE_PATH:
							case Variant::SIGNAL:
							case Variant::STRING_NAME:
								break;
							
							case Variant::DICTIONARY:
							case Variant::VARIANT_MAX:
								break;
						}
						if (error) {
							push_error(vformat(R"(Invalid index type "%s" for a base of type "%s".)", index_type.to_string(), base_type.to_string()), p_subscript->index);
						}
					}
				} else if (base_type.kind != GDScriptParser::DataType::BUILTIN && !index_type.is_variant()) {
					if (index_type.builtin_type != Variant::STRING && index_type.builtin_type != Variant::STRING_NAME) {
						push_error(vformat(R"(Only String or StringName can be used as index for type "%s", but received a "%s".)", base_type.to_string(), index_type.to_string()), p_subscript->index);
					}
				}
				
				result_type.builtin_type = Variant::NIL;
				result_type.kind = GDScriptParser::DataType::BUILTIN;
				result_type.type_source = base_type.is_hard_type() ? GDScriptParser::DataType::ANNOTATED_INFERRED : GDScriptParser::DataType::INFERRED;