### 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)

p_subscript->reduced_value = p_subscript->attribute->reduced_value;
			} else if (!base_type.is_meta_type || !base_type.is_constant) {
				valid = base_type.kind != GDScriptParser::DataType::BUILTIN;
#ifdef DEBUG_ENABLED
				if (valid) {
					parser->push_warning(p_subscript, GDScriptWarning::UNSAFE_PROPERTY_ACCESS, p_subscript->attribute->name, base_type.to_string());
				}
#endif
				result_type.kind = GDScriptParser::DataType::VARIANT;
				mark_node_unsafe(p_subscript);
			}
		}
		if (!valid) {
			GDScriptParser::DataType attr_type = p_subscript->attribute->get_datatype();
			if (!p_can_be_pseudo_type && (attr_type.is_pseudo_type || result_type.is_pseudo_type)) {
				push_error(vformat(R"(Type "%s" in base "%s" cannot be used on its own.)", p_subscript->attribute->name, type_from_metatype(base_type).to_string()), p_subscript->attribute);
			} else {
				push_error(vformat(R"(Cannot find member "%s" in base "%s".)", p_subscript->attribute->name, type_from_metatype(base_type).to_string()), p_subscript->attribute);
			}
			result_type.kind = GDScriptParser::DataType::VARIANT;
		}
	} else {
		if (p_subscript->index == nullptr) {
			return;
		}
		reduce_expression(p_subscript->index);
		if (p_subscript->base->is_constant && p_subscript->index->is_constant) {
			
			bool valid = false;
			Variant value = p_subscript->base->reduced_value.get(p_subscript->index->reduced_value, &valid);