Stale MutationObserver records abort callbacks for active observers

Description

The MutationObserver manager explicitly tolerates stale native records when an observer is disconnected between commit and mount. However, encountering one missing registration returns from the entire notification pass, dropping every later record and callback in the same native batch, including records for still-active observers.

Expected behavior

A stale record for a disconnected observer should be ignored while notification continues for all active observers in the batch, matching the equivalent ResizeObserver handling.

React Native Version

0.87.1 and current main

Affected Platforms

New Architecture - All

まず MutationObserver のマネージャーを見つけてその通知パスを読み、次に issue に記載されている ResizeObserver の同等の処理と比較します。登録が存在しない場合は無視され、同じネイティブバッチ内で後から処理されるアクティブな observer にも引き続きコールバックが渡されることを確認してください。