Work around test failure due to stub_storage_settings issue

For some reason, `stub_storage_settings` causes issues with using `dig`.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/285449

config/object_store_settings.rb

@@ -132,7 +132,7 @@ class ObjectStoreSettings
 
       # If a storage type such as Pages defines its own connection and does not
       # use Workhorse acceleration, we allow it to override the consolidated form.
-      next if allowed_storage_specific_settings?(store_type, section)
+      next if allowed_storage_specific_settings?(store_type, section.to_h)
 
       # Map bucket (external name) -> remote_directory (internal representation)
       target_config['remote_directory'] = target_config.delete('bucket')