Start migrating error.js to TypeScript

src/matrix/storage/idb/Store.js

@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import {QueryTarget} from "./QueryTarget.js";
-import {IDBRequestAttemptError} from "./error.js";
+import {IDBRequestAttemptError} from "./error";
 
 const LOG_REQUESTS = false;
 

src/matrix/storage/idb/utils.ts

@@ -15,7 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { IDBRequestError } from "./error.js";
+import { IDBRequestError } from "./error";
 import { StorageError } from "../common";
 
 let needsSyncPromise = false;