windows/msvc: Use same default python command as core.
<PyQstrDefs>$(PySrcDir)qstrdefs.h</PyQstrDefs>
<QstrDefsCollected>$(DestDir)qstrdefscollected.h</QstrDefsCollected>
<QstrGen>$(DestDir)qstrdefs.generated.h</QstrGen>
+ <PyPython Condition="'$(PyPython)' == ''">$(MICROPY_CPYTHON3)</PyPython>
<PyPython Condition="'$(PyPython)' == ''">python</PyPython>
<CLToolExe Condition="'$(CLToolExe)' == ''">cl.exe</CLToolExe>
<PyClTool>$([System.IO.Path]::Combine(`$(CLToolPath)`, `$(CLToolExe)`))</PyClTool>
