### 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)

}
		}
	} else if (!p_is_lambda && function_name == GDScriptLanguage::get_singleton()->strings._static_init) {
		
		GDScriptParser::DataType return_type;
		return_type.kind = GDScriptParser::DataType::BUILTIN;
		return_type.builtin_type = Variant::NIL;
		p_function->set_datatype(return_type);
		if (p_function->return_type) {
			GDScriptParser::DataType declared_return = resolve_datatype(p_function->return_type);
			if (declared_return.kind != GDScriptParser::DataType::BUILTIN || declared_return.builtin_type != Variant::NIL) {
				push_error("Static constructor cannot have an explicit return type.", p_function->return_type);
			}
		}
	} else {
		if (p_function->return_type != nullptr) {
			p_function->set_datatype(type_from_metatype(resolve_datatype(p_function->return_type)));
		} else {
			
			
			GDScriptParser::DataType return_type;
			return_type.type_source = GDScriptParser::DataType::INFERRED;
			return_type.kind = GDScriptParser::DataType::VARIANT;
			p_function->set_datatype(return_type);
		}
#ifdef TOOLS_ENABLED
		
		
		GDScriptParser::DataType base_type = parser->current_class->base_type;
		base_type.is_meta_type = false;