### 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)

if (base_type.kind != GDScriptParser::DataType::BUILTIN) {
					base_type.builtin_type = Variant::OBJECT;
				}
				switch (base_type.builtin_type) {
					
					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:
						result_type.kind = GDScriptParser::DataType::VARIANT;
						push_error(vformat(R"(Cannot use subscript operator on a base of type "%s".)", base_type.to_string()), p_subscript->base);
						break;
					
					case Variant::PACKED_BYTE_ARRAY:
					case Variant::PACKED_INT32_ARRAY:
					case Variant::PACKED_INT64_ARRAY:
					case Variant::VECTOR2I:
					case Variant::VECTOR3I:
					case Variant::VECTOR4I:
						result_type.builtin_type = Variant::INT;
						break;
					
					case Variant::PACKED_FLOAT32_ARRAY:
					case Variant::PACKED_FLOAT64_ARRAY:
					case Variant::VECTOR2: