🐛 [#3688] Properly access the 'formio-like' data

Accessing dotted-keys like foo.bar in the underlying data
structure used by FormioData does not work, the point of
FormioData is to abstract this access.

src/openforms/registrations/contrib/objects_api/submission_registration.py

@@ -400,12 +400,7 @@ def get_object_data(
  }
  )
 
- variables_values = FormioData(
- {
- **dynamic_values,
- **static_values,
- }
- ).data
+ variables_values = FormioData({**dynamic_values, **static_values})
 
  variables_mapping = options["variables_mapping"]
  record_data: dict[str, JSONValue] = {}