Fix Nighyly for 5.3 branch

Ensure that all uploaded builds have at least 64 bits

Modified name of jobs running one one arch. This is simplified in CI to emphasize on the Arch and not the app type (as in reality "win32" apps can be built in 64 bits...)

In CI :

win32 = 32bits

win64 = 64bits

win3264 = multiarch 32/64 bits

Now run vs2022-ninja-win64-windows both in mr and nightly, to be able to run tests

Re-enabled Nightly Xamarin