Backport of software-mansion/react-native-reanimated#10435 (shipped in Reanimated 4.7.1) to the 4.5.1 that Expo 57 pins. On React Native 0.86 Reanimated applies synchronous prop updates by reflection and skips the view-existence guard, so every view tag that unmounted with buffered updates threw RetryableMountingLayerException on each event dispatch and printed a full stack on the UI thread. The guard checks MountingManager.getViewExists first and skips writes to missing native views.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
(cherry picked from commit ff31b6e5b9)