Update documentation URLs (#49208)

dev/docs/platform_integration/lib/ios.dart

diff --git a/dev/docs/platform_integration/lib/ios.dart b/dev/docs/platform_integration/lib/ios.dart
index 0aeffd8..9645423 100644
--- a/dev/docs/platform_integration/lib/ios.dart
+++ b/dev/docs/platform_integration/lib/ios.dart
@@ -2,5 +2,5 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/// [Flutter platform integration APIs for iOS.](https://docs.flutter.io/objcdoc/)
+/// [Flutter platform integration APIs for iOS.](https://api.flutter.dev/objcdoc/)
 library iOS;