Remove unnecessary @override

Change-Id: I48d2d1e3324838e2814f566de937db6cb061b12f
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/132308
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
Auto-Submit: Mike Fairhurst <mfairhurst@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer/lib/src/workspace/simple.dart b/pkg/analyzer/lib/src/workspace/simple.dart
index ba316fb..5933878 100644
--- a/pkg/analyzer/lib/src/workspace/simple.dart
+++ b/pkg/analyzer/lib/src/workspace/simple.dart
@@ -19,7 +19,6 @@
   /// The [ResourceProvider] by which paths are converted into [Resource]s.
   final ResourceProvider provider;
 
-  @override
   Map<String, List<Folder>> packageMap;
 
   /// The absolute workspace root path.