remove deprecated `author` section (#85036)

packages/flutter_tools/lib/src/commands/update_packages.dart

@@ -1511,7 +1511,6 @@ environment:
     ..writeAsStringSync('''
 name: sky_engine
 version: 0.0.99
-author: Flutter Authors <flutter-dev@googlegroups.com>
 description: Dart SDK extensions for dart:ui
 homepage: http://flutter.io
 # sky_engine requires sdk_ext support in the analyzer which was added in 1.11.x

packages/flutter_tools/test/general.shard/update_packages_test.dart

@@ -15,7 +15,6 @@ import '../src/common.dart';
 // An example pubspec.yaml from flutter, not necessary for it to be up to date.
 const String kFlutterPubspecYaml = r'''
 name: flutter
-author: Flutter Authors <flutter-dev@googlegroups.com>
 description: A framework for writing Flutter applications
 homepage: http://flutter.dev
 
@@ -50,7 +49,6 @@ dev_dependencies:
 
 const String kExtraPubspecYaml = r'''
 name: nodeps
-author: Flutter Authors <flutter-dev@googlegroups.com>
 description: A dummy pubspec with no dependencies
 homepage: http://flutter.dev
 
@@ -60,7 +58,6 @@ environment:
 
 const String kInvalidGitPubspec = '''
 name: flutter
-author: Flutter Authors <flutter-dev@googlegroups.com>
 description: A framework for writing Flutter applications
 homepage: http://flutter.dev