Format all Nix files using the officially approved formatter,
making the CI check introduced in the previous commit succeed:
nix-build ci -A fmt.check
This is the next step of the of the [implementation](https://github.com/NixOS/nixfmt/issues/153)
of the accepted [RFC 166](https://github.com/NixOS/rfcs/pull/166).
This commit will lead to merge conflicts for a number of PRs,
up to an estimated ~1100 (~33%) among the PRs with activity in the past 2
months, but that should be lower than what it would be without the previous
[partial treewide format](https://github.com/NixOS/nixpkgs/pull/322537).
Merge conflicts caused by this commit can now automatically be resolved while rebasing using the
[auto-rebase script](8616af08d9/maintainers/scripts/auto-rebase).
If you run into any problems regarding any of this, please reach out to the
[formatting team](https://nixos.org/community/teams/formatting/) by
pinging @NixOS/nix-formatting.
Using cat relies on coreutils (or equivalent) being in $PATH, which is
not always true.
We could write ${pkgs.coreutils}/bin/cat but in this case we can get by
with the 'read' builtin
While here, cleanup a bit to avoid the x/bin/x patterns we can easily
avoid:
- use lib.getExe for anki-sync-server
- use writeShellScript instead of writeShellScriptBin
Provide a NixOS module for the [built-in Anki Sync
Server](https://docs.ankiweb.net/sync-server.html) included in recent
versions of Anki. This supersedes the `ankisyncd` module, but we should
keep that for now because `ankisyncd` supports older versions of Anki
clients than this module.
