Cannot override functions with narrowing return type.

[RoniPerson]

Godot version

4.0.beta6

System information

Windows 10

Issue description

When overriding a method of a class it is not possible to change the return type even if the new return type is a valid subtype of the original.

Steps to reproduce

a.gd

extends Object

func foo() -> Node:
    return Node.new()

b.gd

extends "a.gd"

func foo() -> Node2D: # The function signature doesn't match the parent. Parent signature is "Node foo()".
    return Node2D.new()

Minimal reproduction project

override_bug.zip

[Mickeon]

I wonder, how does this work in other languages?

[RoniPerson]

It works in Dart.

I also tested it in Python and TypeScript and it works in both but they would also allow me to return a not compatible type (e.g. String) from the overriden method which seems questionable to me.

[RoniPerson]

Completed per #82477