Replace `windows` with `windows-sys`

[Jake-Shadle]

...when not using winrt feature.

The compile time cost of windows is not too bad compared to windows-sys for the features used by this crate, ~4.4s vs ~0.8s, and unfortunately due to how optional crates and cfg works in cargo we now add the cost of windows-sys when the winrt feature is enabled even though it is not used, but I think the inverse of compiling the heavier windows crate when it's not needed is worse, but it is a tradeoff.