Rollup merge of #106867 - sunfishcode:sunfishcode/std-os-fd-stable-version, r=m-ou-se

Fix the stability attributes for `std::os::fd`.

As `@bjorn3` pointed out [here], I used the wrong stability attribute in #98368 when making `std::os::fd` public. I set it to Rust 1.63, which was when io-safety was stabilized, but it should be Rust 1.66, which was when `std::os::fd` was stabilized.

[here]: https://github.com/rust-lang/rust/pull/98368#discussion_r1063721420