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.

Commencez par examiner l’utilisation existante de typing.Final dans les stubs de la bibliothèque standard ainsi que toute discussion antérieure référencée par l’issue. Utilisez le MyPy primer pour évaluer l’impact de l’application de Final aux constantes de niveau module UPPER_UNDER ; le travail est terminé lorsqu’une politique claire et un périmètre d’implémentation sont convenus.