Bug: [lexical-y] A slot a read-only binding keeps showing is removed when an app edits its line in a remote change's read #9813

@lexical/y: when a local update sets a slot the document cannot store, the binding goes read only and keeps showing it (the editor keeps showing what it cannot store, and leaves later updates as they are, per the docs). If an app's code then edits the slot's host line in the update of a remote change's read (a selectionTransform, or an update queued in the read), the editor reads that line again: the slot is removed and the app's edit is not shown. On the previous main (dfe058a) the slot stayed.

Repro: a paragraph whose text node edits itself during a remote read; set a slot on that paragraph (the binding warns UNSUPPORTED_SLOTS_WARNING and goes read only, the slot shown); a peer edits another line; after sync the slot is gone ($getSlot returns null) and the paragraph shows its stored text.

A cell pinning it as test.fails is in packages/lexical-y/src/__tests__/unit/regressions/DroppedNodeState.test.ts ("a slot kept when the binding went read only stays through a read edit").