fix(windows): link against synchronization

[clason]

Disclaimer: I know virtually nothing about building on Windows. @torque

[clason]

Downstream (Neovim) build passes with this change: https://github.com/neovim/neovim/actions/runs/36870158951/job/110396151088?pr=42072

[torque]

Hmm. Interesting that this library is just called synchronization in the upstream build system. Fiddling around with this, it seems to be the difference between building with MSVC vs mingw for windows. The MSVC debug builds were already broken since ucrtbased is a mingw library, but playing around with this locally it seems straightforward to work with either ABI. No clue if anyone cares about the MSVC ABI on windows for this build system, but we might as well support it.

[clason]

Yes, that threw me as well -- it really is different in CMake and Zig. I tried both names in both systems, and that is the only combination that worked. Let's see if this works for downstream builds.