Expand rules_python's type checking in CI to apply to remaining code

...where type errors are still prone to getting introduced.

Quoting @aignas in https://github.com/bazel-contrib/rules_python/pull/3240#issuecomment-3384929943
> I personally am not against doing type checking against all of the python code within the repo, but that is a fair amount of work that would definitely benefit from community also pitching in. I'll create a place-holder ticket that is reasonably wide (and we already have a CI job that is doing type checking on the runfiles library), so initially we could use something similar in our initial approach.

Commencez par examiner le job CI existant qui vérifie les types de la bibliothèque runfiles et identifiez le code Python restant dans le dépôt qui n’est pas couvert. Le travail est terminé lorsque CI applique la vérification des types à ce code restant sans introduire d’erreurs de type non résolues.

Rédigé par le modèle d'indexation à partir du texte de l'issue.