Fix data import with S3 storage backend (#12973)

* Fix data import with S3 storage backend

Fixes #11117

* Fix formatting

* fix formatting

---------

Co-authored-by: mg <mg@layerx-defence.com>
Co-authored-by: Oliver <oliver.henry.walters@gmail.com>

src/backend/InvenTree/importer/operations.py

@@ -33,7 +33,9 @@ def load_data_file(data_file, file_format=None):
     file_object = data_file.file
 
     if hasattr(file_object, 'open'):
-        file_object.open('r')
+        file_object.open(
+            'rb'
+        )  # opens the file in binary mode so other storage backends work
 
     file_object.seek(0)