Remove nightly features for no_std

[domenukk]

Starting with Rust 1.81, core::errors::Error landed in stable:
https://blog.rust-lang.org/2024/09/05/Rust-1.81.0.html#coreerrorerror

core::net was already stabilized with 1.77.0.

This means we no longer need extra nightly features to build ipnet on no_std.

[domenukk]

Any news? :)

[domenukk]

@jjanowsk this would be useful to have in order to allow crates downstream to be no_std, see for example hickory-dns/hickory-dns#2104

[al8n]

Hi, any updates on this PR? We also need the no_std to be compatible with the stable channel for downstream crates to support no_std.

[krisprice]

Hi @domenukk & @al8n - am I tripping, or could we just drop all uses of std::net::{IpAddr ...} and swap for core::net::{IpAddr ...} and likewise for Error throughout in that case?

[domenukk]

Yeah that's totally right.

The reason to keep the std import around for a while would be to remain backwards compatible with earlier rust versions (so 1.81 no-std or earlier and std will work).

But yes.

[krisprice]

Thanks - I'll swap the imports sometime later - should be published now.

[domenukk]

Thank you! :)