[BUG][Discover-next] Discover UI stuck on 'Searching' after deleting index pattern from Index Management

[ananzh]

Describe the bug

When using Discover with query enhancement enabled, deleting an index pattern from Index Management does not properly update the "Recently selected data" list in Discover. This causes the UI to become stuck in a "Searching" state when attempting to use Discover after deleting an index pattern.

To Reproduce
Steps to reproduce the behavior:

1. Enable Discover query enhancement
2. Add some index patterns and indices (e.g. "aaa*" (default) and "test-flat*")
3. Go to Index Management page
4. Delete the "aaa*" index pattern
5. Return to the Discover page
6. Observe that the "Recently selected data" list still shows the deleted "aaa*" pattern
7. Attempt to use Discover

Expected behavior
After deleting an index pattern: The "Recently selected data" list in Discover should update to remove the deleted index pattern. Discover should function normally without getting stuck in a "Searching" state. The UI should reflect the current state of available index patterns accurately.

OpenSearch Version
main

Dashboards Version
main

Plugins
security-dashboards

Screenshots