This simplifies things a little. Building liblzma with VS2013 probably
still worked but building the command line tools was not supported.
Microsoft ended support for VS2013 on 2024-04.
I understood that if a WTPV is specified, it's often wrong
because different VS installations have different SDK version
installed. Omitting the WTPV tag makes VS2017 default to
Windows SDK 8.1 which often is also missing, so in any case
people may need to specify the WTPV before building. But some
day in the future a missing WTPV tag will start to default to
the latest installed SDK which sounds reasonable:
https://developercommunity.visualstudio.com/content/problem/140294/windowstargetplatformversion-makes-it-impossible-t.html
Thanks to "dom".
Lasse Collin