Remove author from `protobuf/pubspec.yaml`

It is no longer used
diff --git a/protobuf/pubspec.yaml b/protobuf/pubspec.yaml
index 0f6616b..ad484aa 100644
--- a/protobuf/pubspec.yaml
+++ b/protobuf/pubspec.yaml
@@ -1,6 +1,5 @@
 name: protobuf
 version: 1.0.1
-author: Dart Team <misc@dartlang.org>
 description: >
   Runtime library for protocol buffers support.
   Use https://pub.dartlang.org/packages/protoc_plugin to generate dart code for your '.proto' files.