Don't redefine PY_VERSION

It's only needed in the Python script. Python.h defines PY_VERSION
(via patchlevel.h).

Author: vstinner

Tools/build/generate_getbuildinfo.py

@@ -112,7 +112,6 @@ def write_macro(name, value):
         write_macro('TIME', TIME)
         write_macro('COMPILER', COMPILER)
         print(file=fp)
-        write_macro('PY_VERSION', PY_VERSION)
         write_macro('PLATFORM', PLATFORM)
         print(file=fp)
         write_macro('GITBRANCH', GITBRANCH)