migrate from winapi to windows_sys

[sn99]

Migrate from winapi to windows-rs for the following:

1. Winapi is no longer actively maintained (last commit was 9 months ago as of now and 2nd last around 2 years ago) compared to last commit to windows-rs as of few days ago.
2. windows-rs is the official Rust crate for Windows by Microsoft and is supposed to be providing a natural and idiomatic way for Rust developers to call Windows APIs. Some crates like socket2 have already migrated to it.

We can also use the latest version of windows_sys (which is rust-version = "1.46") if the minimum required version is changed in ci/cd.

[nagisa]

Sorry for taking a long time to respond to this PR.

I think it is fine if we bump the MSRV version – upgrading a dependency seems like a reason good enough to warrant it.

It seems like rustc already depends on windows-sys as well, so there are no unresolved license incompatibility or similar such concerns either.

Perhaps the only thing I think we should do is relax the version bounds to something like >=$lowest_version_this_library_builds_with, <$highest_released_version. One of the reasons to do that is that rustc currently pulls in windows-sys 0.36 and so specifying precisely 0.34 will result in dependency duplication (unfortunate!) This was less of a problem with winapi given that there were just 3 versions overall :)

Alternatively, I feel like it wouldn’t be too terrible if we just copied the extern definitions into the crate itself. The API scope stacker depends on is really limited and I definitely wouldn’t lose sleep over having to maintain the 8 functions. But that’s out of scope for this PR.

[nagisa]

Thanks. The test failures are probably rust-lang/rust#103673.