Replace flutter.io with flutter.dev (#30562)

diff --git a/dev/docs/dashing.json b/dev/docs/dashing.json
index 4076446..3e96f0b 100644
--- a/dev/docs/dashing.json
+++ b/dev/docs/dashing.json
@@ -3,7 +3,7 @@
   "package": "flutter",
   "author": {
     "name": "The Flutter Team",
-    "link": "https://flutter.io"
+    "link": "https://flutter.dev"
   },
   "index": "index.html",
   "icon32x32": "flutter/static-assets/favicon.png",