[SP] Add search method disclaimer (#241237)

## Summary

<img width="1173" height="219" alt="Screenshot 2025-10-30 at 09 45 35"
src="https://github.com/user-attachments/assets/c188e774-0884-48ba-9cc4-a245b6803e2f"
/>

Author: jloleysens

src/core/packages/saved-objects/api-server/src/saved_objects_client.ts

@@ -187,6 +187,8 @@ export interface SavedObjectsClientContract {
    * Performs a raw search against the saved objects indices, returning the raw Elasticsearch response
    * @param options {@link SavedObjectsSearchOptions} - options for the search operation
    * @returns the {@link SavedObjectsSearchResponse}
+   *
+   * @deprecated This method is experimental, please do not adopt it for production use cases yet!
    */
   search<T extends SavedObjectsRawDocSource = SavedObjectsRawDocSource, A = unknown>(
     options: SavedObjectsSearchOptions

src/core/packages/saved-objects/api-server/src/saved_objects_repository.ts

@@ -185,6 +185,8 @@ export interface ISavedObjectsRepository {
    * Performs a raw search against the saved objects indices, returning the raw Elasticsearch response
    * @param options {@link SavedObjectsSearchOptions} - options for the search operation
    * @returns the {@link SavedObjectsSearchResponse}
+   *
+   * @deprecated This method is experimental, please do not adopt it for production use cases yet!
    */
   search<T extends SavedObjectsRawDocSource = SavedObjectsRawDocSource, A = unknown>(
     options: SavedObjectsSearchOptions