formatter: remove broken vale configuration

Removes the broken and uncommented value configuration for vale.

While vale can be a valuable tool, we need a working configuration if we
want to use it. Keeping a broken configuration on main is not a
sustainable model.

We can fix it and reintroduce it cleanly at a later stage.

formatter.nix

@@ -41,53 +41,5 @@
       treefmt.programs.ruff.check = true;
       treefmt.programs.ruff.format = true;
 
-      # FIXME: currently broken in CI
-      #treefmt.settings.formatter.vale =
-      #  let
-      #    vocab = "cLAN";
-      #    style = "Docs";
-      #    config = pkgs.writeText "vale.ini" ''
-      #      StylesPath = ${styles}
-      #      Vocab = ${vocab}
-
-      #      [*.md]
-      #      BasedOnStyles = Vale, ${style}
-      #      Vale.Terms = No
-      #    '';
-      #    styles = pkgs.symlinkJoin {
-      #      name = "vale-style";
-      #      paths = [
-      #        accept
-      #        headings
-      #      ];
-      #    };
-      #    accept = pkgs.writeTextDir "config/vocabularies/${vocab}/accept.txt" ''
-      #      Nix
-      #      NixOS
-      #      Nixpkgs
-      #      clan.lol
-      #      Clan
-      #      monorepo
-      #    '';
-      #    headings = pkgs.writeTextDir "${style}/headings.yml" ''
-      #      extends: capitalization
-      #      message: "'%s' should be in sentence case"
-      #      level: error
-      #      scope: heading
-      #      # $title, $sentence, $lower, $upper, or a pattern.
-      #      match: $sentence
-      #    '';
-      #  in
-      #  {
-      #    command = "${pkgs.vale}/bin/vale";
-      #    options = [ "--config=${config}" ];
-      #    includes = [ "*.md" ];
-      #    # TODO: too much at once, fix piecemeal
-      #    excludes = [
-      #      "docs/*"
-      #      "clanModules/*"
-      #      "pkgs/*"
-      #    ];
-      #  };
     };
 }