update: use dart.library.js_interop in place of dart.library.html

Author: minoic

CHANGELOG.md

@@ -5,6 +5,7 @@
 * When the keep alive manager runs into a timeout, it will finish the transport instead of closing
   the connection, as defined in the gRPC spec.
 * Upgrade to `package:lints` version 5.0.0 and Dart SDK version 3.5.0.
+* Update xhr transport to migrate off legacy JS/HTML apis.
 
 ## 4.0.1
 

lib/grpc_or_grpcweb.dart

@@ -13,8 +13,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import 'src/client/grpc_or_grpcweb_channel_web.dart'
-    if (dart.library.io) 'src/client/grpc_or_grpcweb_channel_grpc.dart';
+import 'src/client/grpc_or_grpcweb_channel_grpc.dart'
+    if (dart.library.js_interop) 'src/client/grpc_or_grpcweb_channel_web.dart';
 import 'src/client/http2_channel.dart';
 import 'src/client/options.dart';