remove optional because it's still used in too many places

src/Umbraco.Web.UI.Client/src/packages/documents/documents/recycle-bin/repository/sources/document-recycle-bin.tree.server.data.ts

@@ -50,4 +50,9 @@ export class UmbDocumentRecycleBinTreeServerDataSource implements UmbTreeDataSou
 			);
 		}
 	}
+
+	// TODO: remove when interface is cleaned up
+	async getItems(unique: Array<string>): Promise<any> {
+		throw new Error('Dot not use this method. Use the item source instead');
+	}
 }

src/Umbraco.Web.UI.Client/src/shared/repository/data-source/tree-data-source.interface.ts

@@ -5,5 +5,5 @@ export interface UmbTreeDataSource<ItemType = any, PagedItemType = UmbPagedData<
 	getRootItems(): Promise<DataSourceResponse<PagedItemType>>;
 	getChildrenOf(parentUnique: string | null): Promise<DataSourceResponse<PagedItemType>>;
 	// TODO: remove this when all repositories are migrated to the new items interface
-	getItems?(unique: Array<string>): Promise<DataSourceResponse<Array<any>>>;
+	getItems(unique: Array<string>): Promise<DataSourceResponse<Array<any>>>;
 }