Use built-in tar instead of 7zip on windows.

[deivse]

This removes the implied 7zip dependency in favour of using tar which has been available by default on Windows for a while now, as noted in #883 (See https://techcommunity.microsoft.com/blog/containers/tar-and-curl-come-to-windows/382409).

I needed to change this for my own use, so decided to contribute, hopefully this is acceptable. Imho, requiring windows versions released after 2017/18 is better than requiring 7zip. Alternatively, this can be reworked to try to find both 7zip and tar and decide which one to use, but imo that's overkill considering this is supposed to be replaced by the stdlib implementation (any time now, Apple...)