chore(deps): update dependency @vitejs/plugin-legacy to v4 (#99)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

playground/vue-legacy/package.json

@@ -13,6 +13,6 @@
   },
   "devDependencies": {
     "@vitejs/plugin-vue": "workspace:*",
-    "@vitejs/plugin-legacy": "^3.0.1"
+    "@vitejs/plugin-legacy": "^4.0.1"
   }
 }