Skip Rails proxy for Vite assets

What does this MR do and why?

This MR switches from a GDK host to a Vite host for assets served through Vite:

1. Styles
2. Javascript
3. Fonts
4. HMR

This should address performance issues when using Vite with GitLab's HTTP router.

Related:

• Configure Vite to use HTTPS when HTTPS is enabled (gitlab-development-kit#2452 - closed).
• Move Nginx in front of HTTP router rather than ... (gitlab-development-kit#2382).
• Improve Vite's performance with HTTP router ena... (#520707 - closed).

How to reproduce

1. Update to latest GDK
2. Enable vite
3. Load any page
4. The page should load without errors, HMR should work

Conditions verified

Configuration	Supported
Default config: no HTTPS, no nginx, no custom hostname	✅
Custom hostname	✅
nginx enabled	✅
nginx and HTTPS enabled	✅
HTTPS enabled	✅