Don't restoreSnapshot after chat request fails (microsoft#260671)

I don't know why this code was here, maybe it made sense in Edit mode early on

Author: roblourens

src/vs/workbench/contrib/chat/browser/chatEditing/chatEditingServiceImpl.ts

@@ -254,10 +254,6 @@ export class ChatEditingService extends Disposable implements IChatEditingServic
 			for (const remaining of editsSeen) {
 				remaining?.streaming.complete();
 			}
-			if (responseModel.result?.errorDetails && !responseModel.result.errorDetails.responseIsIncomplete) {
-				// Roll back everything
-				session.restoreSnapshot(responseModel.requestId, undefined);
-			}
 
 			editsSeen.length = 0;
 			editedFilesExist.clear();