Describe the bug:
When attaching multiple events to a new case, enabling 'Auto extract observables' does not add observables properly

Kibana/Elasticsearch Stack version:
9.2

Functional Area (e.g. Endpoint management, timelines, resolver, etc.):
Cases

Steps to reproduce:

1. Generate some events
2. Go to Explore->Host page, select multiple events and add to a new case
3. Populate the form and enable auto extract observables
4. Go the the created case, notice the observables were not added

Current behavior:
Observables are not extracted in bulk adding events

Expected behavior:
Observables should be extracted in bulk adding events

Screenshots (if relevant):