ci: set GENERATE_PYTHON_STUBS on Windows

Author: jcarpent

.github/workflows/windows-conda.yml

@@ -39,6 +39,7 @@ jobs:
           -G "NMake Makefiles" ^
           -DCMAKE_INSTALL_PREFIX=%CONDA_PREFIX%\Library ^
           -DCMAKE_BUILD_TYPE=Release ^
+          -DGENERATE_PYTHON_STUBS=ON ^
           -DPYTHON_SITELIB=%CONDA_PREFIX%\Lib\site-packages ^
           -DPYTHON_EXECUTABLE=%CONDA_PREFIX%\python.exe ^
           ..