Don't use .gitignore when determining what to build/serve/run.

sdk/lib/_internal/pub/test/validator/compiled_dartdoc_test.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:scheduled_test/scheduled_test.dart';
 
 import '../../lib/src/entrypoint.dart';
 import '../../lib/src/validator.dart';
 import '../../lib/src/validator/compiled_dartdoc.dart';
 import '../descriptor.dart' as d;
@@ skipping 84 matching lines @@
           d.file('index.html', ''),
           d.file('styles.css', ''),
           d.file('dart-logo-small.png', ''),
           d.file('client-live-nav.js', '')
         ])
       ]).create();
 
       expectValidationWarning(compiledDartdoc);
     });
   });
-}
+}