### 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)

parser->push_warning(member.variable, GDScriptWarning::GET_NODE_DEFAULT_WITHOUT_ONREADY, is_using_shorthand ? "$" : "get_node()");
						}
					}
				}
#endif
			} break;
			case GDScriptParser::ClassNode::Member::CONSTANT: {
				check_class_member_name_conflict(p_class, member.constant->identifier->name, member.constant);
				member.constant->set_datatype(resolving_datatype);
				resolve_constant(member.constant, false);
				
				for (GDScriptParser::AnnotationNode *&E : member.constant->annotations) {
					resolve_annotation(E);
					E->apply(parser, member.constant);
				}
			} break;
			case GDScriptParser::ClassNode::Member::SIGNAL: {
				check_class_member_name_conflict(p_class, member.signal->identifier->name, member.signal);
				member.signal->set_datatype(resolving_datatype);
				
				
				MethodInfo mi = MethodInfo(member.signal->identifier->name);
				for (int j = 0; j < member.signal->parameters.size(); j++) {
					GDScriptParser::ParameterNode *param = member.signal->parameters[j];
					GDScriptParser::DataType param_type = type_from_metatype(resolve_datatype(param->datatype_specifier));
					param->set_datatype(param_type);
					mi.arguments.push_back(PropertyInfo(param_type.builtin_type, param->identifier->name));
					
				}
				member.signal->set_datatype(make_signal_type(mi));