build(test-app): update Svelte and Vite dependencies

Replace @sveltejs/adapter-auto with @sveltejs/vite-plugin-svelte and update Svelte and Vite to latest major versions in test-app. This ensures compatibility with Svelte 5 and Vite 6.

Author: brodienguyen

packages/svelte5/test-app/package.json

@@ -6,7 +6,7 @@
     "type-check": "svelte-check --tsconfig ./tsconfig.json"
   },
   "devDependencies": {
-    "@sveltejs/adapter-auto": "^3.2.0",
+    "@sveltejs/vite-plugin-svelte": "^6.2.0",
     "@tsconfig/svelte": "^5.0.4",
     "nodemon": "^3.0.0",
     "svelte": "^5.0.0",