Update mock sdk to fix test

test/checker/inferred_type_test.dart

Index: test/checker/inferred_type_test.dart
diff --git a/test/checker/inferred_type_test.dart b/test/checker/inferred_type_test.dart
index 8d8210452299e143ee40cb551507540b38df9cfb..28d933635f1f252bec9d962023307f6b6de809d0 100644
--- a/test/checker/inferred_type_test.dart
+++ b/test/checker/inferred_type_test.dart
@@ -623,8 +623,8 @@ void main() {
 
         // We're not properly inferring that map.keys is an Iterable<String>
         // and that x is a String.
-        for (var x in /*info:DynamicCast should be pass*/map.keys) {
-          String y = /*info:DynamicCast should be pass*/x;
+        for (var x in map.keys) {
+          String y = x;
         }
       }
       '''