fix(nufmt): match .nu files instead of unrecognized type tag

[Malix-Labs]

Summary

Fixes the nufmt hook configuration so it can actually run under pre-commit.

Context

In b915811 (#699 by @asakura), the nufmt hook was introduced with types = [ "nushell" ];.

However, pre-commit validates file type tags against the identify tag registry. Because identify does not define a nushell tag, enabling nufmt currently causes pre-commit to crash during configuration validation:

An error has occurred: InvalidConfigError:
==> File .pre-commit-config.yaml
==> At Config()
==> At key: repos
==> At Repository(repo='local')
==> At key: hooks
==> At Hook(id='nufmt')
==> At key: types
==> At index 0
=====> Type tag 'nushell' is not recognized.  Try upgrading identify and pre-commit?

Solution

Following the convention of other hooks in this repository for file formats not tracked by identify (e.g. Elm, Dhall, OPAM, Typst), replace types = [ "nushell" ]; with:

files = "\\.nu$";

(Since types defaults to [ "file" ] in modules/hook.nix, this properly restricts nufmt to Nushell source files without triggering identify validation errors).

Verification

Tested with a consumer flake importing this modified git-hooks.nix with pre-commit.settings.hooks.nufmt.enable = true;. Pre-commit successfully invoked nufmt on .nu files and passed all checks.

[Malix-Labs]

Alternatively: I opened pre-commit/identify#609, so if it is merged, we would just need to update our dependency to it to get support for nushell

[Malix-Labs]

Also I think some tests would be good for this repo maybe, such blatant bugs would be easily caught

Update: created #740 for it