procutil: move stdin assignment outside of try-finally block There is an stdin variable in the global scope of this module. And in the `finally` block of this try-finally statement we're checking `if stdin is not None`. Let's make sure we don't confuse code check tools into thinking we want to use global stdin by moving this line of code outside of `try`. This was caught by pytype 2023.11.21 on Python 3.11.2.