feat: upgrade Vite from v5 to v7 (#7566)

## Summary

Update vite to version 7, this is prerequisite to support sparkjs
https://sparkjs.dev/ for 3DGS file.

Currently, vite 5 has issue to load the file in spark, as working with
developer from World lab https://www.worldlabs.ai/, we found it is bug
on vite 5, we should upgrade vite to latest one.

see https://github.com/Comfy-Org/ComfyUI_frontend/issues/4061

also discussed with @christian-byrne and got approval for this change

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7566-feat-upgrade-Vite-from-v5-to-v7-2cb6d73d365081f7bdb0d7425d8b869e)
by [Unito](https://www.unito.io)

vite.config.mts

@@ -170,6 +170,8 @@ export default defineConfig({
         target: DEV_SERVER_COMFYUI_URL,
         ...cloudProxyConfig,
         bypass: (req, res, _options) => {
+          if (!res) return null
+
           // Return empty array for extensions API as these modules
           // are not on vite's dev server.
           if (req.url === '/api/extensions') {