### Godot version

v4.0.rc1.official [8843d9ad3]

### System information

Lubuntu

### Issue description

You can't use + or += to mutate typed arrays.

It seems to be not correctly getting the type information from the second operand.

An erudite poster on the discord puts it differently:
> it's more like operator + doesn't retain Array typing
> the syntax for Array Concatenation via operators, but the idea gets across i think


The error you see is:
```Trying to assign an array of type "Array" to a variable of type "Array[int]".```


### Steps to reproduce

```
	var Alice: Array[int] = [1,2,3]
	var Bob: Array[int] = [4,5,6]
	Alice += Bob
```
This will crash with the above error message.

### Minimal reproduction project

[plus_syntax_broken_demo_project.zip](https://github.com/godotengine/godot/files/10694514/plus_syntax_broken_demo_project.zip)

if (found != nullptr) {
						err = resolve_class_inheritance(found, p_source);
					}
				}
				if (err || found == nullptr) {
					push_error(vformat(R"(Could not resolve script "%s".)", script_path), p_source);
					GDScriptParser::DataType error_type;
					error_type.kind = GDScriptParser::DataType::VARIANT;
					return error_type;
				}
				result.kind = GDScriptParser::DataType::CLASS;
				result.native_type = found->get_datatype().native_type;
				result.class_type = found;
				result.script_path = ref->get_parser()->script_path;
			} else {
				result.kind = GDScriptParser::DataType::SCRIPT;
				result.native_type = scr->get_instance_base_type();
				result.script_path = scr->get_path();
			}
			result.script_type = scr;
		} else {
			result.kind = GDScriptParser::DataType::NATIVE;
			if (result.native_type == GDScriptNativeClass::get_class_static()) {
				result.is_meta_type = true;
			}
		}
	}
	return result;
}
GDScriptParser::DataType GDScriptAnalyzer::type_from_metatype(const GDScriptParser::DataType &p_meta_type) {