Consistency with `Final` usage in Standard Library Stubs

Currently usage of typing.Final to indicate constants is mixed throughout the standard library (e.g. some newer stubs will utilize it potentially, but it's left out in other places) Has there been any discussion in the past of experimenting with applying Final to all UPPER_UNDER module stdlib constants?

I think class var constants would require a bit more context on usage, as it might be expected for subclasses to override them, but it could be worth starting with modules and gauging the impact from MyPy primer.

Comienza revisando el uso existente de typing.Final en los stubs de la biblioteca estándar y cualquier discusión previa a la que se haga referencia en el issue. Usa el MyPy primer para evaluar el impacto de aplicar Final a las constantes de nivel de módulo UPPER_UNDER; el trabajo estará terminado cuando se acuerden una política clara y el alcance de la implementación.