[3.0] win32: package: use a more recent WIX from contribs

The LLVM Docker image doesn't include wix because it assumes it's coming from contribs. We can do the same in 3.0 by backporting the parts to use WIX from the contribs. This way all Windows builds are using the same WIX (wine is still required in the Docker).

This is a more recent 3.x version than the one in the 3.0 Docker images. Older wix versions don't support arm64.