### 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)

current_enum = prev_enum;
					if (!member.enum_value.custom_value->is_constant) {
						push_error(R"(Enum values must be constant.)", member.enum_value.custom_value);
					} else if (member.enum_value.custom_value->reduced_value.get_type() != Variant::INT) {
						push_error(R"(Enum values must be integers.)", member.enum_value.custom_value);
					} else {
						member.enum_value.value = member.enum_value.custom_value->reduced_value;
						member.enum_value.resolved = true;
					}
				} else {
					check_class_member_name_conflict(p_class, member.enum_value.identifier->name, member.enum_value.parent_enum);
					if (member.enum_value.index > 0) {
						const GDScriptParser::EnumNode::Value &prev_value = member.enum_value.parent_enum->values[member.enum_value.index - 1];
						resolve_class_member(p_class, prev_value.identifier->name, member.enum_value.identifier);
						member.enum_value.value = prev_value.value + 1;
					} else {
						member.enum_value.value = 0;
					}
					member.enum_value.resolved = true;
				}
				
				member.enum_value.parent_enum->values.set(member.enum_value.index, member.enum_value);
				member.enum_value.identifier->set_datatype(make_enum_type(UNNAMED_ENUM, p_class->fqcn, false));
			} break;
			case GDScriptParser::ClassNode::Member::CLASS:
				check_class_member_name_conflict(p_class, member.m_class->identifier->name, member.m_class);
				
				if (!member.m_class->base_type.is_resolving()) {
					resolve_class_inheritance(member.m_class, p_source);
				}