By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Update the flake inputs, and move the NixCI config into nix-ci.nix 'nix flake update' moves nixpkgs from 2026-05-31 to 2026-08-25 and nixpkgs-25_11 to 2026-06-30, along with every other input. 'nix flake check' passes on the result, so all eight checks build against the newer package sets without any change to the Haskell code. The NixCI configuration moves from the flake's 'nix-ci' output into a 'nix-ci.nix' at the root, which is where NixCI looks first and only falls back to the flake output when no such file exists. Same settings, 'auto-update' and 'cachix', and the move removes the "unknown flake output" warning that every 'nix flake check' used to print. No 'deploy' block. These packages are not published to Hackage: the name 'ical' there belongs to an unrelated BSD3 package by another author who is its sole maintainer, so there are no upload rights, and neither of our packages has the synopsis, description or licence that Hackage requires anyway. Releasing needs a decision about what this library is called before it needs any CI.