(PUP-2382) Remove uneeded 'Win32API' and 'win32/api' requires

There isn't anything local that uses Win32API any longer
This could break modules that assumed `Win32API` had been required: https://github.com/puppetlabs/puppetlabs-registry/blob/master/lib/puppet/provider/registry_value/registry.rb#L1. Modules shouldn't make that assumption, but sadly the might