chore(deps): update dependency unbuild to v3

Author: renovate[bot]

packages/unplugin-eta/package.json

@@ -59,7 +59,7 @@
     "eta": "2.2.0",
     "rollup": "4.38.0",
     "typescript": "5.8.2",
-    "unbuild": "2.0.0",
+    "unbuild": "3.5.0",
     "vite": "5.4.16",
     "webpack": "5.98.0"
   },