CI: Add Windows release jobs

We can't use the old jenkins image anymore since the SSL certificates are too old.

We could fork the image and update it, but this would mean we'd have 3 windows image (master, 3.x, and release) which is not optimal, or we could revert back to the old image version (which includes ssh support), update things there, and push it to the actual registry, but this would be even worst IMHO since that image would be extremely different from the one before (and likely the one after)

Instead this MR adds support for release builds on gitlab, and will automatically start the builds upon tagging.

We might want to use a dedicated runner for those tasks, in which case the tags will need to be adjusted here.

I'm not sure it's worth pushing this to master first, since there won't be any release on that branch.