[issue27696] win_add2path.py does not add user site directory

Changes by SilentGhost : -- components: +Demos and Tools, Windows nosy: +paul.moore, steve.dower, tim.golden, zach.ware stage: -> patch review ___ Python tracker

[issue27696] win_add2path.py does not add user site directory

New submission from Kyle Altendorf: Since the detected user path has the text `%APPDATA%` replaced into it `os.path.isdir()` returns `False`. As a result, the user site path is not added to the `%PATH%` variable. The patch adds `os.path.expandvars()` to the `isdir()` check to resolve this