Enable pyiceberg.table.Table.add_files ns downcasting

pyiceberg/io/pyarrow.py

@@ -2422,6 +2422,8 @@ def _check_pyarrow_schema_compatible(
 
 
 def parquet_files_to_data_files(io: FileIO, table_metadata: TableMetadata, file_paths: Iterator[str]) -> Iterator[DataFile]:
+    from pyiceberg.table import DOWNCAST_NS_TIMESTAMP_TO_US_ON_WRITE
+
     for file_path in file_paths:
         input_file = io.new_input(file_path)
         with input_file.open() as input_stream:
@@ -2432,7 +2434,12 @@ def parquet_files_to_data_files(io: FileIO, table_metadata: TableMetadata, file_
                 f"Cannot add file {file_path} because it has field IDs. `add_files` only supports addition of files without field_ids"
             )
         schema = table_metadata.schema()
-        _check_pyarrow_schema_compatible(schema, parquet_metadata.schema.to_arrow_schema())
+        downcast_ns_timestamp_to_us = Config().get_bool(DOWNCAST_NS_TIMESTAMP_TO_US_ON_WRITE) or False
+        _check_pyarrow_schema_compatible(
+            schema,
+            parquet_metadata.schema.to_arrow_schema(),
+            downcast_ns_timestamp_to_us
+        )
 
         statistics = data_file_statistics_from_parquet_metadata(
             parquet_metadata=parquet_metadata,