Remove unneeded extra key_backup.yaml

data/api/client-server/definitions/key_backup.yaml

@@ -1,22 +0,0 @@
-# Copyright 2026 The Matrix.org Foundation C.I.C.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-title: Key Backup
-type: object
-properties:
-  enabled:
-    type: boolean
-    description: True if the user chose to enable key backup. False if the user chose to disable key backup.
-required:
-  - enabled