[Pkg-rust-maintainers] Bug#1070836: rust-apple-nvram: Switch from rust-nix 0.26 to 0.27

[peter green]

> I got the following error when trying the same thing.
> I have no idea why, since the ioctl_write_ptr and ioctl_read macros are
> still supposed to be around. I can't spot any relevant change in nix
> that would cause this to happen. Help would be appreciated.

The relavent change is.

> All Cargo features have been removed from the default set. Users will
> need to specify which features they depend on in their Cargo.toml.

I've bumped the dependency, added the feature, run the autopkgtest
and uploaded the package.