Rollup merge of #126194 - ChrisDenton:winerror, r=Mark-Simulacrum

Migrate more things to `WinError`

In `library/std/src/sys/pal/windows`, we prefer to use the `WinError` type in place of using either `io::Result` or `unsafe { GetLastError }`. The latter is unsafe and weakly typed whereas the former is larger and requires unwrapping because it returns an `Option`.

I also fixed up a couple of places where we were unnecessarily defining error constants that are already defined.

Author: jieyouxu