Remove hack from BigQuery DTS hook (#23887)

airflow/providers/google/cloud/hooks/bigquery_dts.py

@@ -82,10 +82,7 @@ def _disable_auto_scheduling(config: Union[dict, TransferConfig]) -> TransferCon
                 schedule_options["disable_auto_scheduling"] = True
         else:
             new_config["schedule_options"] = {"disable_auto_scheduling": True}
-        # HACK: TransferConfig.to_dict returns invalid representation
-        # See: https://github.com/googleapis/python-bigquery-datatransfer/issues/90
-        if isinstance(new_config.get('user_id'), str):
-            new_config['user_id'] = int(new_config['user_id'])
+
         return TransferConfig(**new_config)
 
     def get_conn(self) -> DataTransferServiceClient:

setup.py

@@ -367,6 +367,9 @@ def write_version(filename: str = os.path.join(*[my_dir, "airflow", "git_version
     'pandas-gbq',
     pandas_requirement,
     'sqlalchemy-bigquery>=1.2.1',
+    # A transient dependency of google-cloud-bigquery-datatransfer, but we
+    # further constrain it since older versions are buggy.
+    'proto-plus>=1.19.6',
 ]
 grpc = [
     # Google has very clear rules on what dependencies should be used. All the limits below