select proper bitness from pypy externals for windows (#637)

* use win64_14x from pypy externals

* dynamically select pypy externals bitness

* refer to pypy as python in commands

Author: altendky

.github/workflows/ci.yml

@@ -158,7 +158,7 @@ jobs:
           mkdir --parents $(dirname $PYPY_EXTERNALS_PATH)
           hg clone https://foss.heptapod.net/pypy/externals/ $PYPY_EXTERNALS_PATH
           dir $PYPY_EXTERNALS_PATH
-          cd $PYPY_EXTERNALS_PATH && hg update win32_14x
+          cd $PYPY_EXTERNALS_PATH && hg update win$(python -c 'import struct; print(struct.calcsize("P") * 8)')_14x
           echo "INCLUDE=$PYPY_EXTERNALS_PATH/include;$INCLUDE" >> $GITHUB_ENV
           echo "LIB=$PYPY_EXTERNALS_PATH/lib;$LIB" >> $GITHUB_ENV
 #          echo "CL=${{ matrix.PYTHON.CL_FLAGS }}" >> $GITHUB_ENV