### Godot version

Godot 4.0 RC 2

### System information

Windows 11

### Issue description

As the title states you get no autocompletion when statically typing.
Of course the code still works, but it shouldn't be neccessary to cast an object to a type it already is.

### Steps to reproduce

1. Create child class with some functionality
![image](https://user-images.githubusercontent.com/100119945/220173809-0b2b2788-d986-4fa7-815c-444268d09c32.png)

2. Get node in parent class and call childs function
![image](https://user-images.githubusercontent.com/100119945/220174167-5ff3c8e9-863e-4fbd-a3cf-d88d34597b39.png)



### Minimal reproduction project

N/A
found = true;
			} break;
			default:
				break;
		}
	}
	
	if (found && r_type.type.kind == GDScriptParser::DataType::BUILTIN && r_type.type.builtin_type == Variant::NIL) {
		found = false;
	}
	
	
	if (!found && p_expression->get_datatype().is_hard_type()) {
		r_type.type = p_expression->get_datatype();
		if (!r_type.assigned_expression) {
			r_type.assigned_expression = p_expression;
		}
		found = true;
	}
	return found;
}
static bool _guess_identifier_type(GDScriptParser::CompletionContext &p_context, const GDScriptParser::IdentifierNode *p_identifier, GDScriptCompletionIdentifier &r_type) {
	static int recursion_depth = 0;
	RecursionCheck recursion(&recursion_depth);
	if (unlikely(recursion.check())) {
		ERR_FAIL_V_MSG(false, "Reached recursion limit while trying to guess type.");
	}
	
	int last_assign_line = -1;
	const GDScriptParser::ExpressionNode *last_assigned_expression = nullptr;