### 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)

}
						element.resolved = true;
					}
					enum_type.enum_values[element.identifier->name] = element.value;
					dictionary[String(element.identifier->name)] = element.value;
				}
				current_enum = prev_enum;
				dictionary.make_read_only();
				member.m_enum->set_datatype(enum_type);
				member.m_enum->dictionary = dictionary;
				
				for (GDScriptParser::AnnotationNode *&E : member.m_enum->annotations) {
					resolve_annotation(E);
					E->apply(parser, member.m_enum);
				}
			} break;
			case GDScriptParser::ClassNode::Member::FUNCTION:
				for (GDScriptParser::AnnotationNode *&E : member.function->annotations) {
					resolve_annotation(E);
					E->apply(parser, member.function);
				}
				resolve_function_signature(member.function, p_source);
				break;
			case GDScriptParser::ClassNode::Member::ENUM_VALUE: {
				member.enum_value.identifier->set_datatype(resolving_datatype);
				if (member.enum_value.custom_value) {
					check_class_member_name_conflict(p_class, member.enum_value.identifier->name, member.enum_value.custom_value);
					const GDScriptParser::EnumNode *prev_enum = current_enum;
					current_enum = member.enum_value.parent_enum;
					reduce_expression(member.enum_value.custom_value);