Strictly check lists and tuples?

[skogsbaer]

I think it would be more intuitive for students, if types for lists and tuples where checked strictly.

Currently the following example works because the wrongly typed element is never accessed:

def foo(l: list[int]) -> str:
    return "1"

foo([1,"stefan"])

Changing the example like this leads to a failure:

def foo(l: list[int]) -> str:
    return l[1]

foo([1,"stefan"])