Remove dart:mojo.internal library in FlutterTarget

pkg/kernel/lib/target/flutter.dart

Index: pkg/kernel/lib/target/flutter.dart
diff --git a/pkg/kernel/lib/target/flutter.dart b/pkg/kernel/lib/target/flutter.dart
index ea9e7047f210e4951e840cad62d8b0fe5784734f..5673a22a570145ed89a58c602e3bdc8bacc9c529 100644
--- a/pkg/kernel/lib/target/flutter.dart
+++ b/pkg/kernel/lib/target/flutter.dart
@@ -17,7 +17,7 @@ class FlutterTarget extends Target {
   FlutterTarget(this.flags);
 
   bool get strongMode => flags.strongMode;
-  
+
   bool get strongModeSdk => false;
 
   String get name => 'flutter';
@@ -47,7 +47,6 @@ class FlutterTarget extends Target {
         // Required for flutter.
         'dart:ui',
         'dart:jni',
-        'dart:mojo.internal',
         'dart:vmservice_sky',
       ];