onnxruntime

4915191e - Fix build of Python wheel on Windows with single-config generator (#16337)

Fix build of Python wheel on Windows with single-config generator (#16337) ### Description Before this PR, the CMake code assumed that when on Windows a multiple-config CMake generator was used, while on non-Windows there was the assumption of a single-config CMake generator. After this PR this information is obtained from the [`GENERATOR_IS_MULTI_CONFIG`](https://cmake.org/cmake/help/latest/prop_gbl/GENERATOR_IS_MULTI_CONFIG.html) global CMake propery. ### Motivation and Context I discovered this problem when building with Ninja generator on Windows, but I guess this should fix problems also on non-Windows platforms when using a multiple-config generator (such as Xcode on macOS or "Ninja Multi-Config" on all platforms). See https://cmake.org/cmake/help/latest/prop_gbl/GENERATOR_IS_MULTI_CONFIG.html for more info.