Update windows-bindgen to 0.61.0
This updates the automatically generate Windows API bindings. Not much changed this time:
- There's now `Default` implementations for many types, which is convenient. It does however conflict with one place where we implemented a non-zeroed default (to set the length field). But that's no big problem.
- The `--no-core` flag has been renamed to `--no-deps` to more accurately reflect its meaning (i.e. generate all necessary code without requiring additional dependencies).
- The `--link` flag allows us to set the location of the `link!` macro. Currently we use our workspace's `windows_targets` crate but we could move it into library/std using `--link`. However, this would need to be co-ordinated with the `backtrace` crate (which is a separate crate but included in std using `#[path]`). So I've left that for another time.