feat: declare workspaces as null

Signed-off-by: SuZhou-Joe <suzhou@amazon.com>

src/core/server/saved_objects/types.ts

@@ -112,7 +112,7 @@ export interface SavedObjectsFindOptions {
   /** An optional OpenSearch preference value to be used for the query **/
   preference?: string;
   /** If specified, will only retrieve objects that are in the workspaces */
-  workspaces?: string[];
+  workspaces?: string[] | null;
   /** By default the operator will be 'AND' */
   workspacesSearchOperator?: 'AND' | 'OR';
   /**

src/plugins/workspace/server/saved_objects/workspace_saved_objects_client_wrapper.ts

@@ -468,9 +468,9 @@ export class WorkspaceSavedObjectsClientWrapper {
                 [WorkspacePermissionMode.LibraryRead, WorkspacePermissionMode.LibraryWrite]
               ),
             },
-            // By declaring workspaces as empty array,
+            // By declaring workspaces as null,
             // workspaces won't be appended automatically into the options.
-            workspaces: [],
+            workspaces: null,
           })
         ).saved_objects.map((item) => item.id);