[3.13] gh-127182: Fix `io.StringIO.__setstate__` crash when `None` is the first value (GH-127219) (#127262) gh-127182: Fix `io.StringIO.__setstate__` crash when `None` is the first value (GH-127219) (cherry picked from commit a2ee89968299fc4f0da4b5a4165025b941213ba5) Co-authored-by: sobolevn <[email protected]> Co-authored-by: Victor Stinner <[email protected]>