nix copy ipv6 link local error

[blaggacao]

Describe the bug
error: don't know how to open Nix store 'ssh://nixos@[fe80::47%eno1]'

Steps To Reproduce

$ nix copy --to ssh://nixos@[fe80::47%eno1] ...  # copy to a link-local ipv6 address via an interface
error: don't know how to open Nix store 'ssh://nixos@[fe80::47%eno1]'

# while ssh works as expected
$ ssh nixos@fe80::47%eno1

Additional context

• https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04#section-3.3
• https://tools.ietf.org/html/rfc3986#section-3.2.2

This is annoyingly blocking Just Works TM link-local host bootstrapping as per:

• fqdn / domain attribute or cli flag serokell/deploy-rs#75 (comment)
• https://github.com/divnix/devos/pull/168/files#diff-d81e5b8475a162be49a6312f4aa5916404ed543671986b81e4ff849a63110736R103

[ajs124]

This might be a duplicate of #4490

[blaggacao]

Indeed, thanks!