remove plugin nvim-lint

Too slow and the diagnostic does not refresh even when the text has been
changed.
Tested with typos for markdown files.

Author: jdhao

lua/config/nvim-lint.lua

@@ -777,12 +777,6 @@ local plugin_specs = {
       require("config.vim-illuminate")
     end,
   },
-  {
-    "mfussenegger/nvim-lint",
-    config = function()
-      require("config.nvim-lint")
-    end,
-  },
   {
     "xzbdmw/colorful-menu.nvim",
     config = function()