Revert powersync_attachments_helper change.

Author: rkistner

packages/powersync_attachments_helper/pubspec.yaml

@@ -10,7 +10,7 @@ dependencies:
   flutter:
     sdk: flutter
 
-  powersync: ^1.8.0
+  powersync: ^1.7.0
   logging: ^1.2.0
   sqlite_async: ^0.8.1
   path_provider: ^2.0.13