[Pattern Overrides] Fix duplication of inner blocks (#57538)

packages/block-library/src/block/edit.js

@@ -27,7 +27,7 @@ import {
 	store as blockEditorStore,
 	BlockControls,
 } from '@wordpress/block-editor';
-import { getBlockSupport, parse } from '@wordpress/blocks';
+import { getBlockSupport, parse, cloneBlock } from '@wordpress/blocks';
 
 /**
  * Internal dependencies
@@ -205,7 +205,8 @@ export default function ReusableBlockEdit( {
 	// Apply the initial overrides from the pattern block to the inner blocks.
 	useEffect( () => {
 		const initialBlocks =
-			editedRecord.blocks ??
+			// Clone the blocks to generate new client IDs.
+			editedRecord.blocks?.map( ( block ) => cloneBlock( block ) ) ??
 			( editedRecord.content && typeof editedRecord.content !== 'function'
 				? parse( editedRecord.content )
 				: [] );