Kibana version: master

Describe the bug: If the current index pattern contains a scripted field, all regular fields are always shown as empty

Steps to reproduce:

1. Load sample data logs
2. Go to Lens
3. Only hour_of_day is shown as available, all other fields are shown as empty regardless of time range

Expected behavior:
Field existence should be fetched correctly

Any additional context:
This might be a side effect of #82223