Use channels as flake inputs

hahaha did this REALLY just happen to me lol?

warning: error: unable to download 'https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz': Resolving timed out after 5001 milliseconds (curl error code=28); retrying in 380ms ms (attempt 1/3)
error:
       … while updating the lock file of flake 'path:/home/deck/.config/nixos?lastModified=...&narHash=...'

       … while updating the flake input 'nixpkgs'

       … while fetching the input 'https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz'

       error: uri https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz changed final destination from https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz to https://releases.nixos.org/nixos/unstable/nixos-26.05pre.../nixexprs.tar.xz during transfer

did i get this right: the link changed at the same second i tried to update? how rare is that!? lucky me :face_savoring_food:

EDIT: for folks in the future: this is fine btw, just update one more time xd