[Observability] Remove unused type !! (elastic#229277)

## Summary

Fixes elastic/kibana-team#1796

Remove unused  deprecated type.

Author: shahzad31

x-pack/solutions/observability/plugins/exploratory_view/public/application/types.ts

@@ -15,7 +15,6 @@ import type {
   IUiSettingsClient,
   NotificationsStart,
   OverlayStart,
-  SavedObjectsStart,
   ThemeServiceStart,
 } from '@kbn/core/public';
 import { EmbeddableStateTransfer } from '@kbn/embeddable-plugin/public';
@@ -46,7 +45,6 @@ export interface ObservabilityAppServices {
   notifications: NotificationsStart;
   observabilityAIAssistant: ObservabilityAIAssistantPublicStart;
   overlays: OverlayStart;
-  savedObjectsClient: SavedObjectsStart['client'];
   share: SharePluginStart;
   stateTransfer: EmbeddableStateTransfer;
   storage: IStorageWrapper;