Error when applying fix to last error in file about vim-grammarous HOT 4 OPEN

-- configure ltex-ls
require 'ltex-ls'.setup {
  on_attach = on_attach,
  capabilities = capabilities,
  use_spellfile = false,
  filetypes = { "latex", "tex", "bib", "markdown", "gitcommit", "text" },
  settings = {
    ltex = {
      enabled = { "latex", "tex", "bib", "markdown", },
      language = "en",
      diagnosticSeverity = "information",
      sentenceCacheSize = 2000,
      additionalRules = {
        -- download ngrams from
        -- https://dev.languagetool.org/finding-errors-using-n-gram-data.html
        languageModel = '~/ngrams/',
        enablePickyRules = true,
        motherTongue = "en",
      },
      disabledRules = {
        en = { "EN_QUOTES" }
      },
      dictionary = (function()
        ---- For dictionary, search for files in the runtime to have
        ---- and include them as externals the format for them is
        ---- dict/{LANG}.txt
        ----
        ---- Also add dict/default.txt to all of them
        local files = {}
        for _, file in ipairs(vim.api.nvim_get_runtime_file("dict/*", true)) do
          local lang = vim.fn.fnamemodify(file, ":t:r")
          local fullpath = vim.fs.normalize(file, ":p")
          files[lang] = { ":" .. fullpath }
        end
--
        if files.default then
          for lang, _ in pairs(files) do
            if lang ~= "default" then
              vim.list_extend(files[lang], files.default)
            end
          end
          files.default = nil
        end
        return files
      end)(),
    },
  },
}