fix(highlight): Use TS built-in is_enabled function (#1513)

The function just replicated the logic from is_enabled and assumed the
`disable` setting is always a table. This is no longer the case
(https://github.com/nvim-treesitter/nvim-treesitter/pull/2009), it can
now also be a function.

lua/telescope/previewers/utils.lua

@@ -96,11 +96,11 @@ end
 
 local treesitter_attach = function(bufnr, ft)
   local lang = ts_parsers.ft_to_lang(ft)
-  if ts_parsers.has_parser(lang) then
-    local config = ts_configs.get_module "highlight"
-    if vim.tbl_contains(config.disable, lang) then
+  if not ts_configs.is_enabled("highlight", lang, bufnr) then
     return false
   end
+
+  local config = ts_configs.get_module "highlight"
   for k, v in pairs(config.custom_captures) do
     vim.treesitter.highlighter.hl_map[k] = v
   end
@@ -113,8 +113,6 @@ local treesitter_attach = function(bufnr, ft)
     vim.api.nvim_buf_set_option(bufnr, "syntax", ft)
   end
   return true
-  end
-  return false
 end
 
 -- Attach ts highlighter