Remove listKey from TS typings

Summary:
The prop is removed as part of D39589089 (bc5cb7c) (no longer does anything). Remove from the TS declarations.

Changelog:
[General][Removed] - Remove listKey from TS typings

Reviewed By: lunaleaps

Differential Revision: D39650827

fbshipit-source-id: dd9b5eccba1b9f6964a6d60ea5bae9913e8396e3

types/index.d.ts

@@ -5012,8 +5012,6 @@ export interface VirtualizedListWithoutRenderItemProps<ItemT>
 
   keyExtractor?: ((item: ItemT, index: number) => string) | undefined;
 
-  listKey?: string | undefined;
-
   /**
    * The maximum number of items to render in each incremental render batch. The more rendered at
    * once, the better the fill rate, but responsiveness my suffer because rendering content may