fix(vue): ensure css treesitter installed (#4308)

## Description

If css treesitter is not installed(the current), <style> in vue file
will use wrong commentstring, ts-comments.nvim or
nvim-ts-context-commentstring both. so ensure it's installed.

## Related Issue(s)

explained: [in
https://github.com/JoosepAlviste/nvim-ts-context-commentstring/issues/117](https://github.com/JoosepAlviste/nvim-ts-context-commentstring/issues/117#issuecomment-2287909324)
close https://github.com/LazyVim/LazyVim/issues/4292

lua/lazyvim/plugins/extras/lang/vue.lua

@@ -11,7 +11,7 @@ return {
 
   {
     "nvim-treesitter/nvim-treesitter",
-    opts = { ensure_installed = { "vue" } },
+    opts = { ensure_installed = { "vue", "css" } },
   },
 
   -- Add LSP servers