Remove tag from allocatedViewRegistry in destroyUnmountedShadowNode (#56274)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/56274

When a ShadowNode is destroyed (e.g. from a superseded concurrent render
or React Transition), destroyUnmountedShadowNode calls Java
destroyUnmountedView which deletes the view from tagToViewState. However,
the C++ allocatedViewRegistry was not updated, leaving a stale entry.

This causes a crash when a subsequent executeMount encounters a Create
mutation for the same tag: allocatedViewTags.contains(tag) returns true
(stale entry from preallocate), so the Create mount item is skipped.
But the Java view was already destroyed. When subsequent mount items
(Insert, UpdateState, etc.) try to reference the tag, getViewState()
throws RetryableMountingLayerException because the tag is not in
tagToViewState.

The fix mirrors what the normal Delete mutation path already does
(line 638: allocatedViewTags.erase(tag)) - ensuring allocatedViewRegistry
stays in sync with the Java-side tagToViewState.

Changelog: [Android][Fixed] - Fix crash from stale preallocated view registry after concurrent render cancellation

Reviewed By: lenaic

Differential Revision: D98729251

fbshipit-source-id: 1a837138622b29bb62e31fb67aacb2c9ff4e9e5d