See #6342: this PR is the ideal, what should eventually be merged. However, it cannot be merged yet. The following changes would need to be made first by someone else (@theuni?):
gitian-win.ymlwould need to be changed to output one single tarball with everything needed for the signing, as in the OS X processgitian-win-signer.ymlwould need to be changed to use said tarball
gitian-win.ymlwould need to be changed to include -unsigned in the installer file names